In this paper, the intelligent weight charging system of heavy loaded highway was developed using piezoelectric quartz sensors, combined with the improved ETC system, in order to solve the congestion problem in highway toll station caused by heavy load vehicles. By study of the effects of different layout and spacing of sensors on the dynamic weighing accuracy and speed, then the optimal layout system of sensors was raised. Real vehicle test was carried out in Changwu charging station of highway from Fuzhou to Yinchuan. Experimental results show that: the optimized sensors enable heavy load vehicles passing through the toll stations in speed of 30km/h,and the accuracy of weighing was maintained within ± 2.5%. And the optimized sensors are able to overcome the errors caused by illegal operations, reaching the purpose of highway congestion management.