The living environment is getting worse， the threat target tends to be hidden and the mission is complex and arduous in modern battlefield. In order to save the lives of soldiers and improve the operational efficiency， the ground reconnaissance robots have become the necessary equipment for the army to turn to non-contact， asymmetric and zero-casualty mode. Starting from the actual engineering application scenarios， a mobile chassis of backpack reconnaissance robot is developed based on four-driven track mechanism. The motion model is established and the feedback control law of mobile chassis system is designed. Finally the test of obstacle-climbing stability and trajectory tracking is carried out. The experimental results indicate that the mobile chassis could have strong obstacle climbing performance and accurate trajectory tracking ability which would meet the requirements of backpack-reconnaissance robot. The paper provides engineering design experience for later robot integration development.