The semi-active suspension with adjustable damping in the cab of a commercial vehicle can make the vehicle get better ride comfort under various driving conditions.In previous studies, the control strategy of the cab suspension was studied, taking the cab as an individual isolated body, and the control accuracy was at lower level.A ten degree-of-freedom vibration model of the whole vehicle was established by integrating all the parts of the vehicle into a whole model.Based on this, the control algorithm of the cab semi-active suspension system was explored.Considering the hysteretic characteristics of the system and the algorithm characteristics, two algorithms, the Smith-proportional integral derivative（PID）and the fuzzy adaptive PID, were proposed.The results show that the controllers based on the two algorithms can effectively restrain the vibration responses of the cab.Between them, the fuzzy adaptive PID is superior to the Smith-PID in the control of cab vibration response, the control force curve is smoother, and the peak suppression effect on its PSD curve is more obvious.All of the above results have been verified by road test.