A pantograph and catenary model considering the overlap is established to study the influence of the height of crossing point of overlap on the dynamic characteristics of pantograph and catenary. The overlap is optimized by reducing the height of crossing point of overlap from 40 mm to 20 mm. The dynamic response between the pantograph and the catenary was calculated when the pantograph passes through two types of overlap at different operating speeds. The ANSYS modal solution method was used to solve the natural frequencies of the catenary at the first 50th order before and after the optimization of the overlap. The results show that reducing the height of crossing point provides a new solution for reducing the dynamic uplift of the contact wire and contact force between pantograph and catenary to a certain extent. In addition, the change in the height of crossing point of overlap affects the vibration characteristics of the catenary, further affecting the dynamic interaction relationship between the pantograph and the catenary, which is also reflected in the frequency domain response of contact force and uplift.