The boiler is a high efficiency and energy saving product. It uses the way of circulation fluidized bed combustion, which can burn bitumite, anthracite or brown coal of low calorific value. The combustion efficiency reaches up to 95%-97%. If the fuel had high content of sulfur, adding limestone into furnace can obviously reduce sulfur dioxide emission and lessen corrosion and pollution caused by flue gas. The staged combustion reduces Nox emission and its slag can be an additive of cement. The boiler uses water tube with natural circulation, and circulation combustion system composed by cyclone separator. Its furnace is the structure of membrane wall: 7 fin water walls in front. The superheater has two stages of high and low superheater. The high temperature superheater is divided into cold section and hot section, a spray desuperheater arranged in middle, and economizer and primary & secondary air preheater arranged at the end. The inside boiler house has two floors, if it need semi-outdoor arrangement, it should be calculated and design of boiler structure and add necessary protective measures. The operation elevation is 8m. The boiler structure is all mental structure, and when seismic intensity more than degree 7, boiler structure should be reinforced.