The invention discloses a gas-fired water heater with a remote temperature adjustment function. The gas-fired water heater comprises two hot water outlets. The combustion power of the gas-fired water heater is changed through the method that the flow amounts of two paths of hot water are controlled remotely through a water valve. The water opening hot water temperature of the water heater is controlled through the method that the combustion power is compensated by combining inlet cold water temperature and inlet cold water flow. When the hot water flow of the first hot water outlet is increased relatively and the hot water flow of the second hot water outlet is reduced relatively, the temperature is controlled to be increased. When the hot water flow of the first hot water outlet is decreased relatively and the hot water flow of the second hot water outlet is increased relatively, the temperature is controlled to be lowered. A wired or wireless remote control is not needed, remote adjustment on the hot water temperature of the gas-fired water heater can be achieved, and the adjustment result is stable and reliable.