The chain grate boiler is a grated fired boiler with a high degree of mechanization, the chain grate is the combustion equipment. The working principle is to drive the chain grate to rotate by the reducer, so that the solid fuel can be fired from the front to the end of the boiler, and the combustion efficiency is greatly improved compared with the fixed grate. When the chain is turned to the bottom, the air cooling lower the temperature, which can protect the grates from burning loss.