Elastic locking device of power supply connecting piece

An elastic locking device of a power supply connecting piece comprises a power supply socket, the power supply socket comprises a socket body and a limit seat which is enclosed outside the socket body and is provided with an upper opening, one side of the limit seat is provided with an extension part, and a gap for a power supply plug to insert is formed between the socket body and the limit seat; the elastic limiting arm is arranged in the extending part of the limiting seat, the elastic limiting arm is connected with the spring, and the elastic limiting arm can transversely move under the action of external force and can abut against the limiting step or the conical outer surface of the power plug to lock the power plug after the power plug is inserted into the elastic limiting arm; and at least two sides of the outer surface of the power plug are provided with limiting steps, or the outer surface of the power plug is in a big-end-down cone shape. According to the invention, the locking of the power plug an