The split path transmission system is applied in the fields of aero and nautical engineering successfully, due to its advantages including high load capacity, large transmission ratio and compact structures. To ensure the balance of load-sharing on each path is the key issue of split path transmission system. In the paper, the load-sharing characteristics of split path transmission system which is equipped on helicopter is investigated via gear system dynamics. The errors of gear profiles, clearances, elastic deformations as well as other factors are taken into account in the model. Several feasible solutions are proposed to enhance the load-sharing performance based on a series of in-depth parametric studies.