To solve the high output press overshoot and low control accuracy problem existed in gasliquid press machine of single channel controlled mode, a gasliquid press machine equipped with dualchannel and dualaperture modes was designed based on the gasliquid pressure technology, while the speed of press was controlled by the bigger aperture channel and the accuracy was controlled by the smaller one. In order to study the dualchannel gasliquid press machines features, the gas mass flow model and boost process mechanical model were established on basis of gasliquid control system. For the sake of obtaining the cutoff pressure of auxiliary channel and the maximum deviation of output pressure, the models were simulated with different air pressures and various main channel orifice areas under Matlab/Simulink. The simulation results show that with the invariable cutoff pressure of auxiliary channel and the same main channel orifice area, the higher the air pressure goes, the greater the maximum deviation is; with the same air pressure, the smaller of main channel orifice areas size is, the smaller of maximum deviation is. To verify the feasibility of the cutoff pressure of auxiliary channel and the maximum deviation of output pressure, a testing platform was set up. The test result shows that the maximum deviation of output pressure is consistent with simulation result. The cutoff pressure of auxiliary channel from the simulation can be used as a basis for designing the dualchannel gasliquid press machine in practical applications.