The invention provides a synchronous belt wheel. Mounting grooves are uniformly distributed around a wheel shaft support plate; wheel shafts are fixedly welded in the mounting grooves; all the wheel shafts are annularly arranged around the wheel shaft support plate; the middle parts of the wheel shafts are welded in the mounting grooves; annular synchronous belt limiting blocks are fixedly weldedat the left ends of all the wheel shafts; positioning holes are annularly arranged in the synchronous belt limiting blocks; and the left ends of the wheel shafts, annularly arranged, are inserted in the annular-arranged positioning holes for fixed welding. The wheel shafts are fixedly welded in the mounting grooves uniformly distributed around the wheel shaft support plate; every two wheel shaftsare spaced; the wheel shafts are fixedly welded in the positioning holes of the synchronous belt limiting blocks; because of gaps between the wheel shafts, gaps between the synchronous belt limiting blocks and the wheel shaft support plate, and hollow holes, such garbage as sand and stones can be leaked to prevent blockage or wear of the synchronous belt wheels; and outer ends of the synchronous belt limiting blocks exceed the wheel shafts to limit and stop the synchronous belts to prevent deviation or fall of the synchronous belts, so that the product quality is improved.