The invention relates to an automatic testing system for yaw drivers, and belongs to the technical field of wind power generation equipment. The testing system comprises at least one testing unit andan integrated control module, wherein the testing unit comprises a first motor and a second motor, the first motor is in shaft connection with the second motor, the first motor is used for being controlled by the first tested yaw driver, the second motor is used for being controlled by the second tested yaw driver, the integrated control module is used for being in communication connection with all the tested yaw drivers so as to test the hardware functions of all the tested yaw drivers, the integrated control module is used for controlling each tested yaw driver to execute the corresponding hardware function test according to a hardware function test starting command, receiving feedback information of each tested yaw driver, and making judgement according to the feedback information to realize the hardware function tests. According to the automatic testing system, all the testing units are integrated in the integrated control module, the comprehensive tests of the hardware functions of the yaw drivers are realized, and the delivery quality of the yaw drivers is guaranteed to reach the standard.