The utility model relates to a sand prevention sealing mechanism for submersible motors, which belongs to the technical field of motor prevention and protection. The inlet end surface of a sand flinging ring of a sand prevention mechanism forms an oblique conical surface, and the sand prevention mechanism is designed for solving the problem that fine sand enters a submersible motor during use, which causes the submersible motor to be damaged. A triangular ring-shaped cavity is arranged in the sand flinging ring, the ring-shaped cavity is provided with small holes which are communicated with the outer side of the sand flinging ring, and the small holes are discontinuously connected with or not connected with the inner side of the sand flinging ring; the inner side at the top of the sand flinging ring is provided with an oblique conical surface, openings of two framework oil seals are outward and separated by a sealing bush, grease lubricant is filled between the two oil seals, and sand blocking discs are pressed and arranged on the oil seals. The structure can effectively prevent the fine sand from entering the submersible motor, and the service life of the submersible motor is improved.