The invention relates to a combined type wide-range high-resolution microcomputer rheostat. The microcomputer rheostat comprises an upper microcomputer, and three mutually series-wound sliding rheostats with jointed ranges, wherein the upper microcomputer is connected with the sliding rheostats through cables; and a wide-range rheostat is formed by the combination of the three rheostats with jointed ranges. The wide-range rheostat is small in size, however, the resolution of the rheostat can be quite high, and the highest resolution is determined by the rheostat with the highest resolution among the three sliding rheostats combined through series connection in the series-wound and combination manner; in setting the resistance values of the sliding rheostats, the resistance value of the rheostat can be set on the microcomputer, and the microcomputer automatically regulates the resistance values of the three sliding rheostats so as to obtain the numerical value required by the upper microcomputer. The combined type wide-range high-resolution microcomputer rheostat can be widely applied to various fields relating to rheostats.