The invention relates to a polishing process for an ultrahigh-resistivity zone-melting silicon polished wafer. Wax-free single-surface polishing is adopted in the process and comprises rough polishing and fine polishing; the rough polishing and the fine polishing are respectively carried out according to pressure and time parameters set in four steps; the polishing solution temperature of the rough polishing and the fine polishing is controlled in a range of 30-40 DEG C; and the large disk temperature of a polishing machine is controlled in a range of 40-60 DEG C. In the process, polishing pressure and time suitable for producing an ultrahigh-resistivity silicon wafer are worked out, quality indexes of flatness, and the like of the polished surface of the silicon wafer are improved by adopting wax-free polishing, especially, an wafer adhering agent is discarded, the contamination of organic matter, and the like is reduced to the greatest extent and the polishing wafer is easy to clean, thereby simplifying wax removal cleaning program and equipment, reducing the cost of the polishing silicon wafer and improving the labor productivity.