Abstract: Water inrush is one of the major disasters in coal mine. Aiming at the problems of low efficiency and difficult installation and transportation of emergency drainage equipment in coal mine water inrush rescue at present, a variable wheelbase coal mine water inrush emergency drainage vehicle was designed. and its dynamics was analyzed by RecurDyn software. The virtual prototype model of the emergency drainage vehicle was established in the RecurDyn software, and the simulation of the upward movement and the downward movement of the emergency drainage vehicle with different wheelbase sizes and the maximum slope of 30° was studied by using multi-body dynamics simulation. Influence of Coaxial Distance on Torque of Track Drive Wheel. The research shows that when the wheelbase is larger than 1470mm, there is a difference of 2078N m in the torque of the left and right crawler driving wheels big slope. Therefore, when crawling on a steep road, the load can be biased to reduce the torque difference between the left and right tracks and improve the climbing performance. Through the dynamic analysis of the virtual prototype, a scientific basis is provided for the functional realization and stable operation of the real vehicle.