According to actual contact relationships between the traction plate and stringing pulley in tension stringing construction of transmission lines， a multi-body motion system is constructed including traction rope， traction plate， conductor and double-pulley structure. A contact judgment method between wire rope， conductor， traction plate and double-pulley is then proposed in accordance with the actual situation. Combined with the spatial position relationship between the components， the force expressions of the element node are proposed based on the finite particle method， and the contact forces of the traction plate to the pulley under different contact conditions are obtained by penalty function method， leading to the dynamic calculation method for the contact collision between the traction plate and the double-pulley structure. According to the actual tension stringing construction， variations of pulley loads and swing angles during the contact process are calculated and analyzed. The rules of traction force， maximum contact force， pulley load and swing amplitude are summarized under the influence factors such as suspension length and traction plate thickness. The proposed calculation method can guide the structural design， construction and installation of traction plate and pulley in engineering， and provide technical reference for the construction of transmission lines.