diff --git a/README.md b/README.md
index da64bee..2f80480 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,10 @@ app.py         ----服务器的主程序
 
 ## 更新日志
 
+* 2021年3月17号，后端更新
+
+  * 新增：根据前端传入的电路数据和仿真参数，进行参数转换，调用pyspice执行电路仿真
+  * 待解决：仿真结果传递回前端，进行可视化展示
 * 2021年3月16号，前端+后端更新
 
   * 新增：成功将spice网表和simulation设置参数传入后端
diff --git a/handler/__pycache__/simulation.cpython-36.pyc b/handler/__pycache__/simulation.cpython-36.pyc
index 6888ad5..7c46d4f 100644
Binary files a/handler/__pycache__/simulation.cpython-36.pyc and b/handler/__pycache__/simulation.cpython-36.pyc differ
diff --git a/handler/__pycache__/spice.cpython-36.pyc b/handler/__pycache__/spice.cpython-36.pyc
index 2062b39..c5628ff 100644
Binary files a/handler/__pycache__/spice.cpython-36.pyc and b/handler/__pycache__/spice.cpython-36.pyc differ
diff --git a/handler/simulation.py b/handler/simulation.py
index 02e34da..2b2d386 100644
--- a/handler/simulation.py
+++ b/handler/simulation.py
@@ -1,4 +1,6 @@
 
+import re
+
 #----调用PySpice包----
 from PySpice.Doc.ExampleTools import find_libraries
 from PySpice.Probe.Plot import plot
@@ -19,35 +21,101 @@ class Simulator_CZ :
         self.circuit = Circuit(title)
     
 
-    def Get_Spice( spice ):
-        self.circuit.raw_spice += ".include D:\\Project_2020\\SPICE\\PySpice\\libraries\cmos\\180nm_cmos.mod" 
-        self.circuit.raw_spice += spice 
+    def Get_Spice(self, spice ):
+        the_circuit = ".include D:\\Project_2020\\SPICE\\PySpice\\libraries\cmos\\180nm_cmos.mod \n" 
+        the_circuit += spice
+        self.circuit.raw_spice = the_circuit
     
 
-    def Sim(sim_type,properties):
+    def Sim(self, sim_type,properties):
+
         parameter = self.Properties_Parse(sim_type,properties)
+        print("parameter:\n",parameter)
         self.simulator = self.circuit.simulator(temperature=25, nominal_temperature=25)
+        # print('simulator:\n',self.simulator)
         if(sim_type == 'transient'):
             self.analysis = self.simulator.transient(step_time = parameter['step_time'],
                                                      end_time = parameter['end_time'],
                                                      start_time = parameter['start_time'],
                                                      max_time = parameter['max_time'], 
                                                      use_initial_condition = parameter['use_initial_condition'])
-            pass
+            print(self.analysis)
+            return self.analysis
         elif(sim_type == 'dc' ):
             pass
         elif(sim_type == 'ac' ):
             pass
         else:
             pass
+        
     
-    def Properties_Parse(sim_type,properties):
+    # 属性解析
+    def Properties_Parse(self, sim_type,properties):
         parameter = {}
         if(sim_type == 'transient'):
-            parameter["step_time"] = 0
-        pass 
-    
-    def unit_transform(value_raw):
+            parameter["step_time"]  = self.unit_tran(properties["step_time"])
+            parameter["end_time"]   = self.unit_tran(properties["end_time"])
+            parameter["start_time"] = self.unit_tran(properties["start_time"])
+            parameter["max_time"]   = self.unit_tran(properties["max_time"])
+            parameter["use_initial_condition"] = self.unit_tran(properties["use_initial_condition"])
+
+        elif(sim_type == 'dc' ):
+            pass
+        elif(sim_type == 'ac' ):
+            pass
+
+        return parameter
+
+    # 单位转换函数
+    def unit_tran(self , value_raw):
+        # 匹配数字的正则表达式
+        regInt = '\d+'
+        regFloat  = '^\d+\.\d+'
+        regNumber = regFloat + '|' + regInt
+        pattern_number = re.compile(regNumber)
+
+        # 匹配字符的正则表达式
+        regChars = '([a-z]+)'
+        pattern_char = re.compile(regChars, re.I)
+
+        # 进行数字和单位的提取
+        unit_chars = pattern_char.findall(value_raw)
+        unit_num = pattern_number.findall(value_raw)
+
+        # 进行格式转换
+        # 有单位时的情况
+        if(unit_chars != []):   
+            the_unit = unit_chars[0]
+
+            if the_unit in ['true','TRUE','True']:
+                return True
+            
+            elif the_unit in ['false','FALSE','False']:
+                return False
+
+            elif the_unit in ['none','NONE','None']:
+                return None
+
+            elif the_unit in ['us','US','uS','Us']:
+                if(unit_num != []):
+                    the_num = float(unit_num[0])
+                else:
+                    the_num = float(0)
+                return u_us(the_num)
+
+            elif the_unit in ['ms','MS','mS','Ms']:
+                if(unit_num != []):
+                    the_num = float(unit_num[0])
+                else:
+                    the_num = float(0)     
+                return u_us(the_num)      
+         # 无单位时的情况
+        else:  
+            if(unit_num != []):
+                the_num = float(unit_num[0])
+            else:
+                the_num = float(0)            
+            return the_num
         pass
 
 
diff --git a/handler/spice.py b/handler/spice.py
index ad54cc6..3977768 100644
--- a/handler/spice.py
+++ b/handler/spice.py
@@ -29,18 +29,19 @@ class SimulationHandler(AuthBaseHandler):
 
         properties = properties_transform(properties_str)
 
-        print("sim type:",sim_type)
-        print("property:",properties_str)
-        print("spice   :",spice)
+        # print("sim type:",sim_type)
+        # print("property:",properties_str)
+        # print("spice   :\n",spice)
 
-        # simulator = Simulator_CZ()
-        # simulator.Get_Spice(spice)
+        simulator = Simulator_CZ()
+        simulator.Get_Spice(spice)
+        analysis = simulator.Sim(sim_type,properties)
 
+        print('simulation finished !')
 
         self.write("success")
 
 
-
 def properties_transform(properties_str):
     properties = {}
     attributes = properties_str.split(";")