Objective: through the analysis of the foot pressure parameters of the elderly with different fall risks before and after the obstacle crossing, to explore the gait dynamics characteristics of the elderly with different fall risks before and after the obstacle crossing, so as to provide theoretical basis and technical guidance for the fall prevention and control of the elderly population and reduce the exercise risk. Methods: Twenty-seven elderly people in community were graded as fall risk (HF: high-risk group and LF: low-risk group) by using the time up and go test (TUG) and five times sit to stand test (FTSST). The foot pressure parameters of the elderly before and after crossing the obstacle were measured and analyzed by footscan USB2 foot pressure measurement system in Belgium. Results: (1) There was no significant difference between the HF group and the LF group before and after the obstacles. But in the second half of the support, the curve fluctuation and support time of the elderly in the HF group were significantly longer than those in the LF group. The COP trajectory of the HF group after crossing the obstacle in the X direction was significantly greater than that of the LF group (P <0.01). (2) The peak pressure of the third metatarsal of the supporting foot before crossing the obstacle was higher in the HF group than in the LF group (P <0.05). The peak pressure of the first phalanx supporting the foot after crossing the obstacle was significantly lower in the HF group (P <0.01), while the lateral heel impulse HF group was significantly larger than the LF group (P <0.05). (3) The distribution rules of the contact area of ??the foot of the elderly in the HF group and the LF group before and after crossing the obstacle were basically the same, and there was no significant difference in the contact area of ??each region (P> 0.05). Conclusion: The results show that the support time of the elderly with high fall risk is longer than that of the elderly with low fall risk when crossing obstacles, the peak pressure of the plantar metatarsal region of the crossing leg increases, and the plantar pressure center curve shows asymmetry and increases in the transverse range of the coronal plane. It is suggested that strengthening the strength of the lower limb swing muscle group of the elderly and proper exercise of lateral movement ability can play a positive role in preventing falls of the elderly.