Provided are a correction device and method for a digital-to-analog converter, a numeric control system, and a numeric control machine tool. The correction device (11) comprises a superordinate machine (110) and a subordinate processor (111) connected to the superordinate machine (110). The subordinate processor (111) is further connected to the digital-to-analog converter (12). The digital-to-analog converter (12) performs digital-to-analog conversion on digital measurement values to obtain multiple actual analog values; the superordinate machine (110) performs linear fitting using least squares on said actual analog values and theoretical analog values corresponding to the digital measurement values. The subordinate processor (111) corrects the digital values to be converted on the basis of the linear equation fitted by the superordinate machine (110), and transmits the corrected digital values to be converted to the digital-to-analog converter (12) for digital-to-analog conversion. The method enables correction using software and removes the step in which the superordinate machine sequentially transmits sampled actual analog values to subordinate processors, thereby accelerating algorithmic calculations, conserving hardware cost, and achieving real-time correction.