The invention discloses an integral forming method of an engine composite shell with a spray pipe. By a winding mode, the spray pipe and the engine composite shell are integrally formed, the circumstance that after being formed independently, an engine composite shell and a spray pipe are connected with each other by metal in the prior art is canceled, the spray pipe is integrally combined to a rear joint of the engine composite shell, after the spray pipe is assembled in place, a convergence section of the spray pipe and the engine composite shell are wound and formed together, a winding layer replaces the original spray pipe metal shell, components such as the rear joint of the engine composite shell, the spray pipe metal shell and connecting pieces are omitted, and the mass ratio of the engine can be increased effectively. A technological sealing head and a fixing block are adopted, limitation of the throat diameter of the spray pipe to a core formwork and a core shaft is overcome, and an axial gap of the spray pipe and control to coaxiality between the spray pipe and the shell can be guaranteed well. In addition, the integral forming method of the engine composite shell with the spray pipe is simple, convenient to operate, short in period and low in cost.