Abstract: Abstract: At present, the main way of fruit harvesting is still dominated by manual picking. Although the workload of the laborer can be reduced by the use of mechanical equipment in the process of fruit harvesting, the unstable harvesting rate and the high proportion of fruit damage are hindering the development of harvesting equipment, especial in fruit harvesting machines, which are the key factors to improve harvesting machine. In order to improve the performance of harvesting equipment in the market of agricultural machinery, it is necessary to make accurate evaluation of the fruit motion in process of picking with fruit harvesting equipment, and then determine the main stages and key factors leading to fruit damage. In this paper, a flattened electronic fruit based on Orange Impact Recording Sensor (OIRS) was designed to detect the mechanical impact caused by the three-dimensional vibration harvesting system and analyze the fruit motion. The dynamics model of sugar orange was built and analyzed, which was equivalent to solve nonhomogeneous linear ordinary differential equation with constant coefficients. The dynamics model was solved and the theoretical condition of fruit abscission from tree body was obtained. The fruit falling process was recorded by high-speed photography in the detachment test of electronic fruit, and the amplitude and binding force of fruit were measured. All the parameters in the theoretical model were calculated, and the result of 17.25>11.6 N was obtained, which demonstrated that the normal inertia force of fruit was greater than that of binding force when the fruit was detached from the tree. So the theoretical model of fruit abscission was verified. Three-axis accelerometer was embedded in the OIRS, and was used to detect and record the acceleration in the process of harvesting. And the final resultant acceleration values from three directions were obtained with the method of FFT (Fast Fourier Transformation) by MATLAB. Four vibration harvesting experiments were carried out in orchard filed and recorded the maximum mechanical impact in vibration and falling stage, the maximum mechanical impact recorded by the electronic fruit was 217 g in the vibration stage, and the average impact reached 123 g. The maximum mechanical impact was 155 g in the falling stage, and the average impact was only 76 g. The results showed that the possibility of fruit damage in the vibration stage was higher, and the potential damage risk can be reduced by adjusting and improving working parameters of the harvesting machine. The higher impact caused by the fruit contact with the ground during the falling stage can also lead to fruit damage, in order to reduce the fruit damage during the falling stage, the damping and buffer materials can be used on the surface of fruit collect equipment. The use of electronic fruit can detect the mechanical shock effectively caused by the vibratory fruit harvesting mechanism with three-dimensional excitation in the fruit picking process, and it can be also used to evaluate damage in the process of harvesting fruit of the machine system. Though there are some differences in fruit size, weight and the way to fixed in fruit tree branch when comparing the actual picking environment and state, experiment results of mechanical harvest using electronic fruit technique in orchard filed demonstrate that this electronic fruit device has practical value and provides a reference for the improvement of the other fruits harvesting machine.