The invention discloses a precision evaluation method and service life prediction method for a numerically controlled machine tool based on a meta-action unit and an integrated subjective-objective weight. According to an FMA structural decomposition method, structural decomposition is carried out on a numerically controlled machine tool, main static error indicators of the numerically controlledmachine tool are clustered to a corresponding meta-action unit, and a degradation rate of each error indicator is calculated; and with Shannon entropy and AHP methods, objective weights and subjectiveweights of the error indicators are determined, an integrated weight of the error indicators is calculated under the condition of the given relative importance of the subjective and objective weights, and a precision degradation condition and the prediction precision service life of the numerically controlled machine tool are evaluated by using the degradation rate of each error indicator. With the disclosed method, the overall accuracy of the numerically controlled machine tool can be evaluated and the precision service life of the numerically controlled machine tool can be predicted; the precision and the precision service life of the numerically controlled machine tool can be obtained; and the guidance of controlling the precision of the numerically controlled machine tool is provided.