In China, the intelligent level of corn harvesters is low, and the parameters of corn harvesters are mostly adjusted trough mechanical levers, the moisture content of corn is high during harvest in most areas, and the corn broken rate and entrainment loss rate of high moisture content corn are high. Thus, a longitudinal axial flow corn harvester was refit intelligently, and an intelligent control system for corn threshing with high moisture content and low loss based on CAN-bus was designed. According to the need of working process of corn harvester, two control modes, manual control and automatic control, were designed, the automatic control strategy was designed，and the discrete PID control algorithm was used to realize the low loss threshing of high moisture content corn. The control strategy test and field experiment of the system were carried out, the control strategy test showed that the working parameters can be adjusted according to the control strategy and were stable in the set threshold value, the field experiment showed that the system can make the broken rate and the loss rate of entrainment meet the national standard, Among them, about the broken rate of corn, the lowest was 3.35%, the highest was 4.05%, and the average was 3.75%; about the entrainment loss rate of corn, the lowest was 1.56%, the highest was 2.08%, and the average was 1.77%.