Based on a certain irreversible flight control system of civil aircrafta model was established for electric control loading system of flight simulator.Taking the elevator system as an examplecentralized processing was made to the distributed subsystem parametersthe mathematical model of flight control system was set upand the composite control method was embedded into the electric control loading system.Simulation experiment was made by using an experiment system developed by our companyand the results was compared with the actual flight test curves of the Boeing Company.The results show that the operating force error is less than 10%the rudder angle deflection angle error is less than 2%which can satisfy the requirement of CCAR60 to the accuracy of flight simulator control loading system.