The invention discloses a slide rail performance testing device and a testing method thereof. The slide rail performance testing device comprises a device support, a linear slide rail, and a supporting rack. The linear slide rail and the supporting rack are fixedly disposed on the device support. A pressing mechanism used for fixing a slide rail to be tested is fixedly disposed on the supporting rack, and a sliding testing mechanism is movably disposed on the linear slide rail, and is used to drive the slide rail to be tested to move for the test. The pressing mechanism and the sliding testing mechanism can be cooperated with each other to complete the performance test of the slide rail to be tested. The testing of the sliding performance of the slide rail can be completed in an automatic way, and the testing efficiency of the slide rail products can be improved, and the investment costs of the human resources of the processing enterprises can be reduced. According to the invention, the structure is simple, and the assembly is easy, and the processing enterprises can acquire the testing device by refitting the conventional production line with low costs, and the application range is wide.