The invention discloses a preparation method of a high-quality sintered rare earth permanent magnet. The preparation method comprises the following steps: burdening a rare earth alloy; performing smelting, hydrogen explosion and hydrogen removal on the rare earth alloy; smashing, grinding and crushing through an air current mill to obtain powder being about 5 microns, and controlling the oxygen content, the nitrogen content and the Ph of the rare earth alloy within certain ranges; performing oriented molding and isostatic pressing under a magnetic field; sintering with the oxygen content in vacuum and protection atmospheres, and keeping the temperature from 700 DEG C or more to 1,000 DEG C or less for 10 minutes or more to 420 minutes or less; adding an appropriate amount of CaCO3, SiO2 and Al2O3 into raw materials; keeping the ratio of material to ball to water at 1:4:1, cooling a ball mill with water during running, detecting the granularity (0.85 to 1 micron) and the pH value (9 to10) during discharging, keeping the temperature from 700 DEG C or more to 1,000 DEG C or less for 10 minutes or more to 420 minutes or less in a sintering procedure; and sintering in the temperature range of 1,000 DEG C or more to 1,200 DEG C or less to obtain the high-quality sintered rare earth permanent magnet of which the average crystallization particle size is 3[mu]m or more to 9[mu]m or less.