There are common problems in Chinese grain combine harvester, such as difficulty in balancing operational performance and efficiency, high failure rate, and low automation level. Feed quantity is one of the important parameters of grain combine harvester, which directly affects the machine's operational performance, overall reliability, and economic benefits. Only when the feeding quantity stabilizes within the rated range can the harvester achieve optimal efficiency. Starting from the fact that feeding amount has a vital impact on machine performance, this paper focuses on the detection function of feeding amount by domestic and foreign combine harvesters with the help of sensing technology. The feeding quantity is mainly reflected by measuring the torque or power of the transmission shaft of key working components through torque sensors and detecting the extrusion force of materials on the mechanical structure shell through pressure sensors. Secondly, machine vision and laser radar technology are used to identify crop density and the bending force of crop stems is measured by force sensor to indirectly represent the feeding quantity. In addition, the reasons that affect the signal processing of feed quantity detection and the key technologies and applications of automatic control of feed quantity in combine harvesters were analyzed and sorted out. Finally, this study proposes the problems existing in the feeding rate detection technology of existing grain combine harvesters, as well as future research priorities and development trends. Although there are many methods for detecting the feeding quantity of domestic combine harvester, they all have low detection accuracy, poor system stability, and are only suitable for a single crop, making it difficult to promote and apply on a large scale. Therefore, there is still great room for improvement in Chinese technology for detecting the feeding quantity of combine harvester. We should increase our research and development efforts on high-precision agricultural sensors and controllers to improve the overall stability of the detection system; The future combine harvester will move towards large-scale, intelligent, and integrated directions.