Many kinds of motors have been made in the current motor. With the explanation of types and styles as well as the continuous refinement of motor functions, various motors which are used in professional field have been born. Measurement of motor performance parameters has always been the focus of research in the motor domain, and measuring range is getting wider and wider. So it is necessary to update the existing motor measuring system. And the development of digital technology and the IT technology brought the spring day to research and development of motor measuring system. This study makes research on scheme which combines the PLC technology and computer technology, effectively using the technical advantages of both technologies. It can quickly make objective and accurate evaluation on the performance and parameters of the motor system, at same time can test the specific parameters according to customer requirements. Therefore, the research on the PLC control system of motor testing system on such basis is of realistic significance and reference value. The presented research on the PLC control system of the motor testing system are based on the idea of modular design, and make modularization segmentation according to the function of the system, making the complex system appear to be clear. The system adopts the CPU of Siemens as the core of PLC control system and combines with the existing situation of motor measurement to make design and optimization of software and hardware, which include the CPU, I/O interface, and communication module and so on. The paper, from a macro point of view, make the systematic study on overall design motor testing system and the design thought of the soft and hardware in the core PLC control system. At the same time, the system program is compiled using modular method, and the software system reflects the high execution efficiency with good maintainability and readability.