By analyzing the conditions of Dayangquan Coal Mine, a permanent refuge chamber was constructed in an abandoned underground. By analyzing the risk factors, the protection functions of the permanent refuge chamber were determined to be heat-resistant, anti-explosion and gas-outburstprevention. The space was divided into buffer area, emergency area and refuge area. The total length of the chamber was determined to be 33 m, the width to be 4.2 m and the effective area to be 138.6 m2 according to the size of magazine, people and equipment. According to the per capita air supply volume, the minimum air supply volume of the compressed air supply system was 14.4 m 3/min for 40 persons. The minimum oxygen supply volume of oxygen generation purifier was 24 L/min. The fireproof antiexplosion airtight system was composed of 4 protection doors which was determined. The study provides reference for the building of permanent refuge chambers with similar scales.