The invention discloses an adhesive for coated abrasive tools. The adhesive is prepared by the following components in parts by weight: 100 parts of water-soluble phenol-formaldehyde resin, 10-12 parts of modified functional resin, and 15-30 parts of a filling agent. A preparation method of the adhesive for coated abrasive tools comprises the following steps: the components are stirred for 0.5-2 hours for mixing, and uniform viscous liquid is prepared. A method for coating the adhesive for coated abrasive tools comprises the following steps: (1) predrying: sand-planting is carried out after gluing, the temperature is raised to 100 DEG C, predrying is carried out for 20 minutes, and the sand grains are positioned; (2) main drying: the adhesive is coated again, heating is carried out at 110-120 DEG C for 2 hours, and a glue-line on the sand face is completely solidified. The method has the beneficial effects that rapid heating can be carried out, once solidification is needed in a drying chamber for completion, secondary solidification in a curing furnace is not needed, time of three days for the secondary solidification and energy consumption thereof are saved, large solidification temperature difference and large chromatic aberration of the product appearance are avoided, chromatic aberration of the product appearance is eliminated, brightness of the product appearance is obviously increased, and toughness of the product is improved.