在电气系统设计过程中利用S7-PLCSIM仿真软件来查看PLC程序的运行状况。首先分析了涡流探伤系统和工艺流程，其次介绍了在涡流探伤电气系统中PLC输入输出信号地址的分配情况，然后基于对S7-PLCSIM界面的描述，利用S7-PLCSIM仿真实际的S7-300 PLC。通过仿真能够发现程序中存在的问题以便及时处理，提高了程序开发的效率，节约了现场的调试时间。实例表明仿真结果与涡流探伤中实际的PLC运行一致，经仿真测试后的程序安全、稳定、可靠。

The S7-PLCSIM can be used to examine the running status of the PLC program in the electrical system design process. First of all, eddy current testing process flow was analyzed, secondly, electrical input and output signals address distribution of the PLC was described. Then based on S7-PLCSIM interface descriptions; practical S7-300 PLC was simulated by using S7-PLCSIM. The problems could be found and dealt with timely in the process of simulation. The program development efficiency was improved and the time for debugging was saved. An example showed that the simulation result was the same as the actual PLC operation. The PLC program after simulation test was safe, stable and reliable.