The invention discloses an energy-saving switchable intelligent environment-friendly heat preservation furnace, and belongs to the field of environment-friendly heat preservation furnaces. The energy-saving switchable intelligent environment-friendly heat preservation furnace can further use two modes to pass through an intermediate frequency coil shell in use. A heating pipe is directly heated, and when the heating pipe is heated to a certain temperature, a water bath heating mode can be adopted to heat materials to a constant temperature; the heat preservation furnace can be quickly heated to reach a specified temperature by combining the two modes and can keep the specified temperature balance; and compared with a single heating mode adopted by a conventional heating device , the two modes are more energy-saving and consumes much less energy than the prior mode; and circulating water can be replaced, so that the liquid constant temperature is changed to achieve different constant temperature modes.