In order to improve task execution efficiency of muti-agent system and reduce costs, the sliding mode controller is designed based on dynamical model of Akerman unmanned vehicle, which realizes the tracking of the expected trajectory by the follower vehicle.The hyperbolic tangent function is adopted to replace the symbolic function in exponential reaching law for ensuring the continuity of the switch function.The convergence of the system is proved based on the new reaching law.A low-cost unmanned vehicle experiment platform is built based on ROS and Raspberry Pi 4B.ROS software is designed, including navigation, mapping, TF transformation and other functions of unmanned vehicle platform.The networking operation is completed for multi-unmanned vehicle system, so that the sensor data of unmanned vehicles can be shared and the relative position information between unmanned vehicles can be obtained through TF transformation.Finally, an experiment is performed on the unmanned vehicle experiment platform according to the sliding mode controller.The formation control performance curve is obtained and analyzed quantitatively and qualitatively.