The invention discloses an unmanned aerial vehicle Picatinny rail mounting mechanism. The unmanned aerial vehicle Picatinny rail mounting mechanism is composed of a body, a pressing block, a locking screw, a nut and a handle and is mainly applied to the field of connection of unmanned aerial vehicles carrying light weapons. The unmanned aerial vehicle Picatinny rail mounting mechanism adopts a technology that the locking screw and the nut are matched with each other to tightly hold the body and the pressing block, and the pressing block and the main body L-type positioning surface are matchedwith each other to clamp a Picatinny rail of a weapon. According to the unmanned aerial vehicle Picatinny rail mounting mechanism, the unmanned aerial vehicle is connected with the Picatinny rail of the weapon byfastening the body, the pressing block, the locking screw, the nut and the handle, disassembly and assembly are very convenient, the structure is simple, realizing is easy, the convenience, reliability and universality of the unmanned aerial vehicle carrying the light weapon are improved, and the unmanned aerial vehicle Picatinny rail mounting mechanism has a great value to be implemented and promoted.