SZL chain grate burning biomass boiler has high efficiency, strong overload capacity and wide adaptability to fuel.Such as: biomass particle, biomass powder, mushroom stick, broken wood, rice husk, peanut shell, etc. The boiler burns biomass solid fuel. The membrane water wall structure is adopted for the water walls on both sides of the furnace; the water wall pipes of the front and back walls of the furnace extend downward to the upper part of the grate to form the front and rear arches, which not only increases the sealing performance of the boiler, but also increases the furnace volume and heating surface, and strengthens the strength of the rear arches. The fuel falls from the coal hopper to the grate, burns after entering the furnace along with the grate, and the flue gas enters the convection tube bundle area and passes through the smoke wall. The flue gas flows to the S-shaped corner. The dust in the flue gas is separated by the inertial action and falls into the four gravity type automatic ash hoppers set below. The fuel falls into the slag hopper along with the grate transportation and the coal slag falls into the slag hopper, and is discharged from the furnace body by the slag extractor.