The invention discloses a preparation method of a composite material thruster stator. The thruster stator is divided into three parts including a propeller hub, paddles and a guide pipe, the roots of the paddles are connected with the propeller hub, tip parts of the paddles are connected with the guide pipe, and the overall thruster stator is made of composite materials. All paddles of the stator achieves paving in a stator paddle die in a prepreg and fiber cloth doping manner, transition fibers in certain sizes are led out at the roots and the tip parts of the paddles from the doped fiber cloth and are used for being subject to connection with the propeller hub and the guide pipe and co-curing molding subsequently, continuity of the fibers in the paddles and the guide pipes is guaranteed, and the molded stator is excellent in overall mechanical property. The composite material thruster stator prepared through the preparation method is small in weight, good in strength, high in reliability, reasonable in structure and simple and practical in molding method.