The invention discloses a chassis height self regulating system and a regulating method; wherein, the self regulating system comprises a suspension height sensor module, a central processing module, a display interactive module, an audio frequency prompt module and an execution module; wherein, the suspension height sensor module detects the suspension height of a chassis in real time, and transmits the change of the suspension height which is detected every time into the central processing module; the central processing module is connected with a bus of a bodywork, receives the running speed information of vehicles in real time, and processes the received information of the suspension height and the running speed of vehicles; according to the processing result, executive information is sent to the execution module for operation, and the suspension height is automatically regulated. The system of the invention can prompt the user when the running speed exceeds the specified value and automatically lowers the height of the chassis to the safe position in a state of default setting, so as to avoid the danger caused by overhigh center of gravity of the vehicles when in high speed travelling; at the same time, the invention improves the comfortableness when in driving, reduces the windage resistance, saves the fuel, and has good development prospect.