Flexible chassis is a four-wheel-independent-drive and four-wheel-independent-steer electric vehicle with four in-wheel motors. In order to resolve some key issues about dynamics of the flexible chassis and find its control strategy, a new type of test bench with four turntables was designed for testing the flexible chassis. The flexible chassis was connected to the bench through two groups of sensors with measurement directions being perpendicular to each other. A measurement and control system based on LabView was developed for the test bench, and it can control and record the rotating speeds and electric current of the eight in-wheel motors and the forces of the four force sensors. Firstly, the whole structure design was completed, the working principle of the device was analyzed and a testing system was developed. Secondly, the bench and assemble observation system were made. Finally, the experiment was carried out. The experiment contained two parts. For the fixed rotation speeds of four wheels of flexible chassis, the changing processes of the rotating speed, electric current and the forces at a rotation speed of 55 r/min were monitored and analyzed with two different movement postures of chassis. For the different rotation speeds, the same indexes were analyzed to find the final results. In different motion states of flexible chassis, it took 2~3 s for in-wheel motors’ rotation speed to increase from 0 to stable state. Tractions of flexible chassis can reach 1 132 N and 1 165 N, respectively, when running up-down and left-right; driving force of each in-wheel motor, running at a constant speed, was different, so real-time automatic adjustment of each in-wheel motors’ current was required to ensure the coordinated movement of each wheel when driving independently. The test results could provide basic data for study of flexible chassis and it also proved that the bench was feasible and efficient. The research results provided theoretical and technical references for design of the new type of test bench.