The invention discloses a multi-fuel thermoelectric conversion device. The multi-fuel thermoelectric conversion device comprises a shell and a turbo generator arranged in the shell. The turbo generator divides an inner cavity of the shell into a high-pressure gas chamber and a low-pressure gas chamber, and the volume of the low-pressure gas chamber is larger than the volume of the high-pressure gas chamber. The high-pressure gas chamber is internally provided with a burner and an evaporation water tank. The burner and the evaporation water tank are nested together, the burner is connected to acombustible gas passage, and a combustion medium is transported to the burner through the combustible gas passage for combustion. The heat generated by the combustion is transmitted to the evaporation water tank nested with the burner, and the evaporation water tank is filled with phase change working media. The high-pressure gas chamber and the low-pressure gas chamber are connected through a water collecting pipe, the water collecting pipe communicates with the evaporation water tank, the shell is close to a valve close to one side of the low-pressure gas chamber, the valve is used for adjusting the pressure of the low-pressure gas chamber, and a condenser is arranged at the end, close to one side of the low-pressure gas chamber, of the shell. The multi-fuel thermoelectric conversion device can solve the problems of narrower fuel selection range, technical difficulty and high realization cost in the prior art.