The invention discloses a modeling and simulating method of a carrier-based aircraft seat strap restraint system, and belongs to the field of aviation biomechanical simulation. Firstly, a finite element model of a seat is built by referring to a certain type of carrier-based aircraft through three-dimensional modeling software and a hybrid grid; the initial state of a Hybrid 3 type dummy model is set according to a standard posture; a hybrid safety belt mode is used, a multi-body model is used from a tensioning mechanism to the shoulder, and the finite element model is used on rest portions; then, the seat, a dummy and a strap model are combined into a human seat strap system model, a seat back inclination angle is set according to the posture in an actual carrier-based aircraft, it is assumed that the seat and the aircraft are in rigid connection, and the contact between the seat and a person and the contact between the seat and the strap are established; finally, according to the blocking carrier landing accelerated speed of the actual carrier-based aircraft, an accelerated speed curve of a bottom plate serves as an input curve of simulation analysis to be applied to the bottom of the seat and input to a calculation model for simulation calculation. The method is capable of evaluating the restraint effect of the strap system and safety risks to pilots.