The invention relates to a device for picking pineapples. The device comprises a two wire switch, a handle, a three-bar clamping position and nut, a battery, a stepping motor, a pineapple cover, a protective cover, a battery clamping position, a protective cover clamping position, an adjusting rod, an adjusting part, a cutting knife, a driver, a control part, a control harness and a clamping position hole, and the control part controls the driver through the two wire switch so as to control the stepping motor to act. Accordingly, the pineapple cover can be matched with the cutting knife to cut and place the pineapples, the structure is small and exquisite, operation is conducted conveniently, the three-bar clamping position and nut can be used for adjusting the height of pineapple cover, users of different heights can use the device conveniently, the battery is detachable, charging is conducted conveniently, the protective cover is arranged, and operation is conducted safely.