In order to reduce the errors caused by human factors and improve the quality and efficiency of Erbium-doped Optical Fiber Amplifier (EDFA) testing, an automatic testing system based on Python is designed to test EDFA transient quickly. According to the working principle and rate equation of EDFA, a reasonable test method is designed according to the cause of transient in actual optical fiber communication process. The interface bus is used to enable the system to control the multiple test instruments by one computer at the same time. Python is used to realize the automatic control of instruments and equipment, and achieve “one-key” automatic storage of test data and graphics of each instrument and equipment. Experiments show that the system has the advantages of high testing accuracy, easy operation and good scalability, which can fully meet the user's requirements for transient testing.