The invention discloses an automatic charging device of an unmanned aerial vehicle. The structure of the device comprises an automatic charging base, a multifunctional tripod, a protection frame, a position indicator, a controller and propellers, the automatic charging base is arranged under the multifunctional tripod, electricity contact connection is adopted, the controller is electrically connected above the multifunctional tripod, the protection frame is installed on the outer side of the propeller, locking connection is adopted, the position indicator is installed above the controller, buckled connection is adopted, the controller is placed on the same level as the protection frame, the propellers are mounted on the four corners of the controller, and screwed connection is adopted. The automatic charging base includes batteries, an auxiliary block, a mini motor, a pressure reducing spring block, a conductive screw rod, a connecting contact, a contact head and a conductive slot, the batteries are mounted on the left and right ends of the lower portion of the mini motor, and wire electrical connection is adopted; when the device is used, through an arranged conductive locking connecting structure, the structure is simple and light, the installation is convenient, the locking is firm, and the charging is safer and more stable.