The invention discloses a health monitoring method for a numerical control machine tool, and the method comprises the steps: (1), executing a self-inspection G instruction, and collecting the operation state data; (2), building the mapping relation between the collected operation state data and the self-inspection G instruction, and forming an instruction domain mapping ensemble; (3), dividing the instruction domain mapping ensemble according to the self-inspection G instruction, extracting the instruction domain mapping under the self-inspection G instruction, obtaining the operation state data under the self-inspection G instruction, calculating an actual characteristic value according to the operation state data, comparing the actual characteristic value with a standard characteristic value, and obtaining a health index through calculation. The method improves the calculation basis of a key health index of the numerical control machine tool, the calculation method of the health index and the display mode of the health index, and can effectively solve a problem that the judgment of the health condition of the numerical control machine tool is not timely and accurate. Moreover, the obtained health index of the numerical control machine tool is displayed in a visualized manner, thereby improving the interaction effect of the numerical control machine tool with a person.