The invention provides a test bench for detecting a braking distance of a vehicle, and a method for determining he braking distance. The test bench comprises a vehicle supporting platform, and the vehicle supporting platform is used for placing a test vehicle body. The vehicle supporting platform comprises a base platform and a rail wheel set, wherein the rail wheel set is rotatingly disposed on the base platform, and the rail wheel set drives the wheels of the test vehicle body to rotate. An initial wheel set is connected with the rail wheel set, and synchronously rotates with the rail wheel set. The test bench also comprises a control system which is used for controlling the vehicle supporting platform and the test vehicle body. The test system is used for detecting the braking distance of the wheels. The test bench is used for measuring the braking distance of the vehicle, and avoids the impact on the normal operation of the vehicle from the operation of directly pulling the vehicle to an operating rail for the testing of the braking distance of the vehicle. The test bench can effectively shorten the test cycle of the braking distance of the vehicle, and improves the calculation precision and reliability of the braking distance of the vehicle.