The traditional hydraulic simulator can not fully simulate the real load, so a mechanical pendulum hydraulic load simulator which can simulate the elastic load was established. The speed of the piston rod and the rotation angle of the pendulum were simulated and verified by MATLAB software. The results show that the piston speed and the pendulum rotation angle of the pendulum load simulator are slightly different from the expected value and the tracking effect is good under the noninterference condition. The tracking error of the piston speed and the pendulum rotation angle of the pendulum load simulator is large at the beginning stage under the interference condition, but the pendulum load simulator can make self-adaptive adjustment quickly to meet the requirements of the expected value. The pendulum load simulator can be used to simulate the velocity change of the actual piston linkage motion of the nozzle.