As we all know, given the movements of left and right wheels to control the position and orientation, the system is a typical nonholonomic system. So a mobile robot with multi-trailers is typical nonholonomic, under actuated system. The path planning problem of the system of this kind cannot be solved using the path planning algorithm for single body car. In this paper, based on repeatedly direct kinematics, we describe the design and kinematics of the tractor-trailer robot system using tiny movements to follow the track from initial configuration to the goal configuration. In this system, we can easily get the best path of tractor-trailer robot system even if the mobile robot cannot make a center rotation.