Abstract: In order to realize the efficient and clean combustion of Fujian anthracite,the design characteristics of the first domestic 145 t/h high-temperature and ultra-high pressure CFB boiler burning Fujian anthracite are analyzed and refined,which are the combination of traditional measures such as high combustion temperature,blast furnace height,low flue gas flow rate and advanced equipments such as steam cooled high-temperature cyclone separator,platen superheater arranged on the upper part of furnace. The operation test of the influence of coal particle size and secondary air rate on the combustion efficiency and boiler load was carried out,and improvement suggestions was put forward. The results show that the combustible content of fly ash carbon is reduced from 12%-15% to 8%-10% by increasing the screen size of screening machine and decreasing hammer head gap of crusher to optimize coal particle size. It is found that there is the best secondary air rate (the test result is 0.45-0.50),which makes boiler load smooth and combustion efficiency high. The optimization improvement of reducing the width of the flue at the inlet of the separator and the recycle combustion of the fly ash of the dust collector was carried out,which improved the boiler load capacity,and the boiler efficiency operation increased by about 1%. It is suggested to shorten the length of the central cylinder,the inner diameter of the central cylinder and the inner diameter of the return riser to improve the separation efficiency. More than five years of operation practice has proved that the design is successful. The annual average operation time is more than 7 550 h,and the annual average load rate reaches 95.35%. The third party test shows that the average thermal efficiency of the boiler under the load of 151 t/h is 90.57%,which provides solid practical evidence for the construction of small capacity and high parameter units.