The invention belongs to the field of design of aviation aircrafts and particularly relates to a propeller. The propeller comprises axial flow blades, a hub, a shaft, a bearing body, an inflow pipe, an outflow pipe, guide vanes and a rear cover, wherein the inflow pipe and the outflow vane are both conical pipes. The propeller has the advantages that under the condition that the outlet area and the flowing of the outlet fluid are the same, the thrust is larger than that of other type propellers.