Smoke-exhausting denitrifying and silencing system of gas internal-combustion engine

The invention discloses a smoke-exhausting denitrifying and silencing system of a gas internal-combustion engine. The smoke-exhausting denitrifying and silencing system comprises a high-temperature smoke-exhausting pipe, wherein the exhausting end of the high-temperature smoke-exhausting pipe is respectively connected with a waste-heat recovery device and a high-temperature smoke bypass pipe; theother end of the waste-heat recovery device is connected with a smoke mixer; the high-temperature smoke bypass pipe is connected with a high-temperature smoke bypass adjusting valve; the other end ofthe high-temperature smoke bypass adjusting valve is connected to the smoke mixer; the smoke-exhausting end of the smoke mixer is connected with a denitrifying and silencing combined device. The smoke-exhausting denitrifying and silencing system disclosed by the invention is simple in structure, high in heat recovery rate, thorough in denitrification and good in silencing effect, and is economicaland environment-friendly.