The invention relates to an injection molding system with the excellent machining quality. The injection molding system comprises a base, a controller, a supporting column, an injection molding mechanism, a drying mechanism and a cleaning mechanism; the cleaning mechanism comprises a cleaning box, a drainage pipe, a discharge pipe, a cover plate and two ultrasonic transmitters, and a lifting assembly, a lifting plate, a first motor, a first driving shaft, a first mesh plate, two brackets and two stirring plates are arranged in the cleaning box; and the drying mechanism comprises a drying box,a delivery pipe, an air outlet pipe and two air inlet pipes, and a vibrating assembly, a supporting assembly, a guiding plate, an electric heating wire and an air guiding assembly are arranged in thedrying box. According to the injection molding system with the excellent machining quality, oil stains and dust on the surfaces of plastic particles are removed through the cleaning mechanism, therefore, the plastic particles are clean, and the injection molding quality is guaranteed; and in addition, water on the surfaces of the particles is removed through the drying mechanism, therefore, the clean and dry plastic particles enter a crucible, excellent plastic product production is facilitated, and the equipment practicability is improved.