A turbotype gas starting device of a diesel engine takes compressed air as air source power. The turbotype gas starting device mainly comprises a casing, an air inlet duct, a turbine driving mechanism, a planetary speed reducer, an isolator and a silencer which are formed into an overall structure, wherein turbotype gas starting adopts a structure consisting of the casing, a turboshaft, a turbine rotor, an inner impeller and an outer impeller; air changes an impact gas flow direction through the inner impeller, the turbine rotor and the outer impeller so as to exert a force moment in the same direction on the turbine rotor, thereby driving the turbine rotor to rotate; meanwhile, the planetary speed reducer is driven to rotate; the isolator undergoes automatic clutching and transmission so as to drive the diesel engine to start; and the silencer can effectively eliminate gas starting noise. The turbotype gas starting device has big starting force moment, quick, efficient, safe, stable and reliable starting, low noise and no lubrication; compared with the prior art, the starting speed of the device can be increased by 100 percent; moreover, the device can be started within 5 to 6 seconds, and is an ideal gas starting device of the diesel engine of a rubber-tired cart suitable for underground operation in severe environment at a coal mine.