Abstract: Abstract: This paper analyzes the main reasons for the low reheat temperature of 660MW ultra supercritical boiler in a power plant, and puts forward the solutions. By reducing the opening of secondary air and central air of each layer of burner, strengthening soot blowing on the boiler heating surface, increasing the intermediate point temperature, reducing the primary air pressure and reducing the burnout air volume, the reheat temperature is effectively increased and the exhaust gas temperature is reduced and the boiler efficiency is improved.