The invention provides a test system of an electric power steering device. The test system is used for performance tests of the electric power steering device, and comprises a host, a real-time computer, a steering system, a load mechanism and an installation bed. The steering system and the load mechanism are arranged in the installation bed. A push rod of the load mechanism is coaxially connected with a gear in the steering system. The host is in communication connection with the real-time computer, and with the electric power steering device in the steering system and the load mechanism through a peripheral plate card in the real-time computer. The invention also provides a test method of the electric power steering device. According to the invention, performance of the to-be-tested electric power steering device can be reflected; a test means is provided for a new strategy; the test period is shortened; and the cost is reduced.