The invention provides a pilot oil source valve. By the aid of the pilot oil source valve, problems of easiness in damage, high failure rate and the like of existing pilot oil source valves can be solved. The pilot oil source valve comprises a valve body and a valve element. A cylindrical valve element cavity is arranged in the valve body, and a backflow oil cavity, an inlet oil cavity and a working oil cavity are sequentially arranged on the inner wall of the valve element cavity at intervals from the top to the bottom; an oil inlet, a return oil port and a working oil port are further formed in the valve body; the oil inlet is communicated with the inlet oil cavity, the return oil port is communicated with the backflow oil cavity, and the working oil port is communicated with the working oil cavity; the valve element is a cylindrical valve element and is divided into a press portion, an upper sealing portion, a connection portion and a lower sealing portion from top to bottom, and both the outer wall of the upper sealing portion and the outer wall of the lower sealing portion cling to the inner wall of the valve element cavity; a cavity is formed between the outer wall of the connection portion and the inner wall of the valve element cavity, is communicated with the inlet oil cavity and is alternately communicated with the backflow oil cavity and the working oil cavity under the ascending and descending actions of the valve element; the press portion extends out of a valve element cavity port in the top of the valve body; a spring is arranged between the bottom of the valve element and the bottom of the valve element cavity.