Abstract: In order to compare the performance of different feeding rate detection methods, and to clarify the characterization degree of the feed rate of the combine harvester by the parameters of different operating conditions, an indirect detection system for the feeding rate was designed, which based on six variables the header drive shaft torque, the threshing drum shaft torque, the bridge floor pressure, the header drive shaft speed,the bridge shaft speed,and the off-drum shaft speed. A system test was carried out with the rice Nanjing 9108 being taken as the test object, and the Zoomlion 4LZT-6. 0ZE combine harvester taken as the test platform. In the test,the output of each sensor was collected by the data acquisition card, and the performance analysis and principal component analysis of the output data were carried out. The test and analysis results show that the overall performance of the torque system is better than that of the pressure system. The main shaft torque of the header,the torque of the threshing drum and the pressure of the bridge bottom plate contribute more than 50% to the change in the feed rate. Among them, the torque of the threshing drum is important for feeding. The characterization degree of the change in the input amount is the highest, and the research results provide a reference for the optimization of the detection method of the combine harvester’s feeding amount.