Methods of simulating G-loads in post-stall maneuvers on a novel sustained G-load flight simulator (SGFS) was studied. Considering features of intense angular motion of the aircraft in post-stall maneuvers, additional G-loads generated by the rotation of the aircraft were also counted in the calculation of G-loads on pilot, which was later employed in the mathematical model for SGFS G-load simulation. G-loads on pilot in a typical post-stall maneuver known as Herbst maneuver were simulated by using the model. SGFS tracked 3-axis G-loads command precisely with the maximal error less than 0.2g during the simulation. The results indicate that additional G-loads on pilot generated by aircraft rotation could not be neglected and show SGFS could meet the requirements of post-stall maneuver G-loads simulation.