Based on the simulation of lunar gravity field, this paper deduced the similar principle and put forward a new method which can simulate the low gravity by change the initial condition of experiment’s data. Then the method of the lunar gravity field simulation based on these laws is presented, and the widely applicability to different lander conditions and lunar soil conditions is proved by calculation examples. Through this method to simulate the low gravity, the prototype of lander can be used with simple equipment and can be made optimization very easily. This method can be used in lunar probe and others planetary probe.