The invention discloses an acceptance inspection method of the mine goaf caving and blasting treatment effect in conversion from underground mining to opencast mining. According to the method, based on the principle of region size balance and rock mass size balance before and after goaf caving and blasting, the size of small goafs remaining after blasting and the goaf filling ratio are worked out, and then the goaf caving and blasting treatment effect is quantitatively evaluated, wherein the goaf filling ratio is used for evaluating the goaf caving and blasting treatment effect and judging whether original main potential hazards are eliminated accordingly, and the size of the remaining small goafs is used for evaluating the level of the potential hazards remaining after goaf caving and blasting treatment. By means of the method, the goaf caving and blasting treatment can be quantitatively evaluated by calculating the size of the remaining small goafs and the goaf filling ratio, and the technical problem that it is difficult to quantitatively evaluate the goaf caving and blasting treatment effect and determine whether the small goafs still remain in loose rock masses after goaf caving and blasting treatment is solved. The method can be widely applied to caving and blasting treatment for goafs detected in the production process from underground mining to opencast mining.