The invention provides a high speed rail train-network model establishment method considering the secondary arcing influence of a pantograph catenary. The method comprises the following steps that: 1) deducing a traction network unit length linked set total [Pi] type network matrix parameter, and establishing a traction network unit length set total [Pi] type linked parameter model; 2) aiming at CRH2 multiple units to establish a multiple unit reflux loop model which comprises three parts including a roof high-voltage cable, a train body and an earthing system; 3) combining with a relative position distribution and electric parameter relationship among the train body, a steel rail and a traction network in a practical operation process of the multiple units; and 4) establishing a train-network analysis model under the secondary arcing influence under a practical multiple unit operation working condition. By use of the model established by the invention, the electric influence of pantograph catenary multiple-time arcing on a whole traction power supply loop can be more effectively analyzed, and meanwhile, the method can be popularized and applied to modeling for other operation working conditions, including passing neutral section, train departure, train arrival and the like, in a traction power supply system and the research of the influence on the whole power system.