A threshing drum feeding measuring system is designed based on the film sensor to realize the realtime feeding volume monitoring of the threshing drum of rice combine harvester. The system can monitor the working state of threshing drum and assist in determining the current realtime feeding quantity by using the thin film sensors to measure the force on the top cover. The bench test was carried out under conditions of 1 100 r/min and a feed rate of 0.2 to 0.8 kg/s,using a small horizontal axial flow threshing drum with a rated feed rate of 0.8 kg/s as test object,the mature Late indica rice 98 and Chuanqi Fengliangyou 1 rice as test materials with the rotational speeds of 650 r/min,800 r/min,950 r/min,respectively. The rated feeding capacity of the platform detachment device was 0.8 kg/s. The results showed that the film sensor was collected. Realtime signal was significantly correlated with realtime feeding. The linear relationship between feeding amount and sensor signal was fitted with good fitting effect. It is indicated that the measuring system designed can measure feeding amount through sensor signal.