The invention discloses a preparation method of precise casting wax mold repair wax. The preparation method comprises the following steps that a, firstly, selected raw materials are processed; b, auxiliary materials are prepared after the step a is finished; c, after the step b is completed, and then heating and fusing are carried out by utilizing a stirrer; d, after the step c is finished, the preparation of the repair wax is carried out; and e, after the step d is completed, finally the repair wax is collected. According to the preparation method, in the process of manufacturing the repair wax, the auxiliary materials are added on the conventional raw materials, white vaseline, rosin, petrochemical engineering resin and stearic acid in the auxiliary materials are utilized, the overall hardness of the repair wax can be increased according to the proportioned proportion, and the adjusting degree is higher, and therefore, different repairing requirements can be met, and the production cost can be effectively controlled; and cooling equipment can be provided for gradually cooling when mechanical fusion is carried out, so that the formation of internal air holes is avoided on the premise that the adhesion performance is improved, the forming speed and the overall density are increased, and popularization and use are facilitated.