The invention belongs to the technical field of a fuel system of an airplane and relates to an oil drainage valve for a fuel system of an airplane. The oil drainage valve for the fuel system of the airplane consists of a shell body, a valve, a limiting device, a spring, a handle and the like; the valve is at the closing and locking position at the beginning; when the valve is opened, the handle is firstly pulled out to be rotated to the opening position and then is loosened, and finally, the valve is locked at the opening position; and when the valve is closed, the handle is pulled out to be rotated to the closing position and then is loosened, and finally, the valve is locked at the closing position. The oil drainage valve for the fuel system of the airplane is opened through rotating the handle; and the reliable locking of the valve is realized under the action of the spring force. The oil drainage valve for the fuel system of the airplane has a simple structure and high reliability, is convenient to operate, effectively improves the maintenance efficiency to the airplane, reduces the maintenance workload and shortens the maintenance period.