The road wheels dynamic load of tracked vehicles directly affects the adhesion and traction performance. A theoretical estimation model of the road wheels dynamic load is established according to the correlation with variable time lag between front and rear wheels， and the coherence between the left and right wheels. Based on multi-body dynamics software RecurDyn， a multi-body dynamics model of tracked vehicles is established and then the model verification is performed. On the basis of the theoretical estimation model and the multi-body dynamics model， the effects of driving speed， road roughness and track shoe parameters on the road wheels dynamic load are analyzed. The results shows that with the increase of driving speed and road roughness， the road wheels dynamic load and dynamic load coefficient linearly increase. The road wheels dynamic load first decreases and then increases with the increase of track shoes width. As the track shoes thickness increases， the road wheels dynamic load linearly increases. The conclusion provides a theoretical basis for the analysis of adhesion performance， structural design and optimization of tracked vehicles.