The invention discloses a mixer in an ethylene-vinyl acetate (EVA) film production system. The mixer comprises a cylindrical shell, wherein the top of the cylindrical shell is provided with a cylindrical shell cover; the bottom of the cylindrical shell is provided with a valve; a main stirring shaft and reagent nozzles are arranged in the middle of the cylindrical shell; turned-up helical blades are arranged on the main stirring shaft; and the top of the main stirring shaft is connected to a motor arranged on the cylindrical shell cover. The mixer is characterized in that a left stirring shaft and a right stirring shaft are arranged respectively beside the main stirring shaft in the cylindrical shell; the left stirring shaft and the right stirring shaft are provided respectively with turned-down helical blades; and the tops of the left stirring shaft and the right stirring shaft are connected to the top of the main stirring shaft by a transmission mechanism. Through stirring cooperation of the main stirring shaft, and the left and the right stirring shafts and the turned-down helical blades arranged at the left and the right stirring shafts, EVA particles in the cylindrical shell can be circularly stirred up and down thereby being fully mixed with reagents injected from the top so that EVA film raw material quality is improved.