The invention provides a fluid energy milling device with a grading function, which comprises a micropowder hopper, a milling chamber, a jet chamber and an output pipeline, wherein the micropowder hopper is connected with the milling chamber, the annular belt type jet chamber is fixed around the milling chamber, a plurality of jet nozzles are uniformly arranged on the outer wall of the jet chamber, outlets of the jet nozzles extend into the milling chamber, the output pipeline is arranged at the center of the upper end face of the milling chamber, and the bottom of the output pipeline is communicated with the milling chamber. The fluid energy milling device is characterized in that the diameter of the output pipeline is enlarged, the center of the lower end face of the milling chamber is provided with an outlet, the outlet is concentric with an inlet of the output pipeline and the diameter of the outlet is more than that of the inlet of the output pipeline, a regulating pipe nipple is arranged at the outlet, the upper end of the regulating pipe nipple extends into the milling chamber and the lower end is fixed with a gravity grader with an opening at the bottom, and the inlet of the output pipeline extends downwards to the middle of the gravity grader. Because the regulating pipe nipple and the gravity grader are additionally provided, the fluid energy milling device has a preliminary function, shortens the subsequent procedure process and reduces the occupied space.