Generator set exhaust gas boiler is the high efficient energy saving equipment for flue gas waste heat recovery of generator sets. The exhaust gas boiler is adopted pin tubes or fin tubes to strengthen the extended heating surface of the heat transfer components, the heating surface of both sides of water pipe can be greatly increased, meanwhile the strong turbulence formed by the flue gas flowing through the surface of tubes can improve the heat transfer efficiency and reduce the soot accumulation, the exhaust gas boiler is with advantages of compact structure, high heat efficiency, long working life, safe and reliable features, simply maintenance. Now it has been used for hundreds of different gas-fired generator sets, achieved considerable economic benefits.