25.4 mV降低到1 mV。Zero-drift of the grain flow sensor leads to a significant error when the combine harvester tilted. The purpose of this paper is to study the effects of combine harvester tilt on the zero-drift of the impact-based grain flow sensor，and propose an innovated grain flow sensor that can stabilize zero-drift when combine harvester titled. With the single plate impact-based grain flow sensor fixed in a combine harvester, the zero-drift voltage of the grain flow sensor is recorded while the combine harvester tilted between -15° and 15°. The test result shows that there is a linear relationship between the zero-drift and the obliquity, and the zero-drift voltage is 25.4 mV when the combine harvester tilted at 15°. A dual-plate differential impact-based grain flow sensor is developed to compensate the zero drift. The tilt experimental results show that the zero-drift of the two plates are consistent each other, and thus the overall zero-drift voltage of the sensor is reduced from 25.4 mV to 1 mV.