Abstract: As the set dates for achieving the "dual carbon" goals draw nearer, new energy power generation is being vigorously developed, and thermal power units will long shoulder the responsibility of peak shaving. A 350 MW unit fully burns Shenhua bituminous coal and adopts a W-flame boiler. However, the existing equipment is unable to meet the requirements of fully burning Shenhua coal type and flexible peak shaving. At present, there is a lack of flexibility transformation plans for boilers burning bituminous coal with W flame. First, conduct a baseline test on the unit to analyze the existing problems of the unit, and then propose a renovation plan. The renovation adopts a comprehensive approach, involving powder-making, combustion, heat exchange surfaces, fans, etc. After the flexibility transformation, it can achieve full combustion of Shenhua coal type, with NO_x lower than 360 mg/Nm³（6%O₂, standard dry basis）, achieve low-load stable combustion at 30%BRL load, and the boiler efficiency is greater than 93.0%.