This paper reported on the parameters optimization and semi-active control of suspension for a case study of heavy duty truck, in order to improve the road friendliness of commercial vehicle. In which, the effects of the suspension parameters on the road friendliness and the ride comfort were investigated based on an established dynamic model of 1/4 vehicle. Based on which, a semi-active control of suspension was studied based on adjustable damping shock absorber, concerning both the road friendliness and ride comfort. The results showed that the optimal fuzzy controlled semi-active suspension can significantly reduce the road damage coefficient and, to some extent, improve the vibration comfort, compared to the passive suspension.