The invention discloses a multi-fuel energy-saving furnace, which comprises a furnace panel (1), a furnace basin (2), a furnace ring (3), a furnace cylinder (6), a furnace outer cylinder (7), and three air inlet partitions ( 8), secondary air inlet pipe (12), furnace foot bottom plate (13), third air inlet pipe (14), ash box (15), fire retaining ring (18), furnace foot side plate (19), return air circle (20), exhaust gas outlet hole (29), tertiary air inlet hole (5), secondary air inlet partition (9), furnace bridge (11), furnace tube secondary air inlet hole (17), primary Air inlet (16), stoker (23), stoker chute (24), stoker insert (25) and furnace cover (26). The invention adopts a fully enclosed structure, forms vaporized combustion through three times of air intake to assist oxygen, greatly improves the combustion value, and has the characteristics of various fuels, high efficiency and energy saving, economical and practical, hygienic and environmentally friendly, and long service life.