Based on the boiler tail flue economizer abrasion, leakage, plugging ash, the actual situation of exhaust temperature on the high side in Yunning Thermoelectricity Company, application of spiral fin tube economizer for high temperature period of boiler economizer was done. The technology eliminated boiler economizer defects, reduced the boiler exhaust temperature and exhaust smoke heat loss, improved the efficiency of the boiler, met the requirement of boiler operation.