The invention provides a water-cooling fast-setting control method of depth distribution of hard 
abrasive in a magnetic 
abrasive metal matrix. The method is characterized in that the lower portion of an atomizing and 
cooling chamber of 
powder mixing gas atomizing fast-setting magnetic 
abrasive preparing equipment is filled with cooling water, the height of the 
water level of the cooling water in the atomizing and 
cooling chamber is adjusted by controlling the water input amount, by adjusting the height of the 
water level of the cooling water in the atomizing and 
cooling chamber, the 
flight distance of 
powder mixed 
molten metal drops is adjusted, then the 
cooling speed of the 
powder mixed 
molten metal drops is adjusted, and the powder mixed 
molten metal drops are cooled so that the hard abrasive can form the magnetic abrasive distributed on the surface shallow layer of a magnetic abrasive 
metal matrix; control over the depth of distribution of the hard abrasive on the surface shallow layer of the magnetic abrasive 
metal matrix is achieved; moreover, the 
flight distance of the powder mixed molten metal drops is shortened greatly, the overall height of an atomizing and condensing chamber and equipment is reduced, and equipment manufacturing cost is reduced; and meanwhile, by means of the shock chilling effect generated by 
water cooling and fast setting, 
bonding strength between the hard abrasive and the metal matrix is improved. The method is simple, stable, reliable and suitable for 
mass production of the high-performance magnetic abrasive.