Aiming at the problems of bucket vibration and high control error in the control process of existing high-precision machine tools,an algorithm based on variable universe fuzzy control was proposed.Based on fuzzy control theory and fuzzy control rules,the dimension of input data was reduced,the domain of input and fuzzy quantity was divided by using computer language,and fuzzy rules were expressed by using fuzzy language; the fuzzy universe was adjusted to avoid excessive oscillation of the system and reduce the deviation between the input value and the theoretical value; after fuzzy reasoning and clear processing,the output data with small deviation were obtained to improve the control accuracy of NC machine tool.The results show that the step response interference of the proposed algorithm is small,and the control error and deviation fluctuation are low.