Aimed at the problems of less data or undefined data in multifunctional minicircular saw worm gear abrasion evaluation process,by using the GM(1,1) model of grey theory,combining with the parameters change of worm gear failure,including noise,working current and temperature,the circular saw worm gear abrasion failure evaluation model was constructed based on grey theory.The evaluation process of the evaluation method proposed was introduced by an example.The feasibility and practicability of the method were also proved.A new prediction method is provided for circular saw worm gear abrasion.