The invention discloses an adhesive for precision machining and a preparation method and an environment-friendly cleaning method thereof. The adhesive is prepared from the following raw materials by weight: 50-65 parts of rosins and derivatives thereof, 10-20 parts of fatty acids and derivatives thereof and 10-30 parts of wax. The preparation method comprises the following steps: placing the rosins and derivatives thereof, the fatty acids and derivatives thereof and the wax into a mixer, discharging the mixture after stirring the mixture at 60-80 DEG C for 15-30min and obtaining the solid adhesive for precision machining after cooling. The adhesive has good melt fluidity and high adhesive strength, is suitable for precision machining of fine parts and can be removed by being soaked in hotalkaline water with concentration of 3% by mass at 70-80 DEG C for 5-30min. The adhesive fully meets the requirements for the adhesive for precision machining, including fast sizing and high adhesivestrength, and utilizes the environment-friendly cleaning method.