Automatic picking of fruit and vegetable crops can not only reduce the physical labor of fruit farmers in the harsh field environment, but also greatly improve the harvesting efficiency. Aiming at the problems of complex and changeable field environment and more damage of clustered citrus fruits after mechanized harvest, a new end actuator of three finger clamping cutting and picking robot is proposed in this study. The end actuator is mainly composed of clamping device and cutting device. The clamping device can realize the lossless clamping of citrus, and the cutting device can realize the rapid separation of fruit and stem. The citrus fruit is clamped and wrapped by a flexible clamping finger and then rotated to make the blade cut the fruit stalk. By analyzing the stress and shape of citrus fruit in the natural environment, the working space and structural parameters of flexible clamping fingers are analyzed, and the control motor is selected according to the stress analysis of clamping fingers. The end effector is mounted on the 6-axis mechanical arm, the stepping motor speed, the end effector speed and the picking angle are taken as the influencing factors, and the single fruit picking time and the picking success rate are taken as the evaluation indexes for the picking performance test. According to the analysis of the test results, it is concluded that the optimal parameters of the end effector are the stepping motor speed of 250r / min, the end effector speed of 160mm / min When the picking angle is 0 °, the picking performance is the best. The end effector of Citrus picking robot developed in this paper has simple structure, stable and reliable operation, and high integration with the manipulator, which can provide a reference for the overall development of Citrus picking robot.