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A wheel type rigid-flexible coupling snapping device was designed to reduce kernel loss on corn head. There were two forms of rigid-flexible coupling structure in the device, namely, buffer spring and flexible contacting surface. The buffer spring was fixed to play a cushioning role when the snapping rolls were impacted by corn ear, and the flexible contacting surface was fixed on the snapping rolls to decrease hardness. In order to explore the different roles that two kinds of rigid-flexible coupling structure played in loss reducing of the designed snapping device, impact experiments of corn ear were conducted to study the mechanisms. The experiments were carried out on the widely used corn head with deck plates and the corn head with wheel type rigid-flexible coupling snapping device respectively. Each of the snapping devices was equipped with steel surface and flexible contacting surface composed of silicon rubber. The impact velocity was determined according to the typical working conditions of corn harvester. The impact parameters, including impact time, peak acceleration and impulse as well as the mass of detached kernels were collected. The result showed that buffer spring could shorten the impact time. Compared with snapping device equipped with deck plates, the impact time of corn ear on wheel type rigid-flexible coupling snapping device were shortened by 62.2% and 67.3%, corresponding to steel surface and flexible surface, respectively. Moreover, the impulse was decreased by 60.6% and 76.0%, and the detached kernels mass was decreased by 14.4% and 25.6%. On the other hand, flexible surface could reduce the ear’s impact force by prolonging impact time. Compared with the steel surfaces, impact time of corn head with flexible contacting surfaces were prolonged by 78.4% and 53.8% corresponding to corn head with deck plates and the one with wheel type rigid-flexible coupling snapping devices, respectively, which caused the declines of peak impact force by 45.1% and 55.2%, impulse reduction by 19.9% and 51.2%, respectively, and resulted in a decrease of detached kernel mass by 34.1% and 42.8%. The research can provide theoretical basis for the designs aiming to reduce kernel loss of corn head.