A cone shaped docking and releasing mechanism provides rigid connection between a parent UAV and a sub UAV to form a spliced double unmanned aerial vehicle system with improved cruising duration ability by providing sub UAV battery with charging function. It comprises a parent UAV, a sub UAV and a docking mechanism with charging ports. The parent UAV and the sub UAV are connected with each other through the docking mechanism to form a double UAV system, the docking mechanism is a cone structure and comprises a charging output component connected with the parent UAV internal control system, a charging circuit connected with a sub UAV control system and a charging input component connected with the charging circuit.