The invention relates to a multi-purpose energy-saving furnace which comprises a box body; the box body comprises a bottom board, an upper wallboard, a front wallboard, a rear wallboard, a left wallboard and a right wallboard; a hole is formed in the left lower part of the front wallboard; a stop lever is arranged on the inner side of the hole; the upper space of the stop lever is a combustion space; a left clapboard is arranged on the right side of the stop lever; an upper clapboard is arranged on the upper side of the left clapboard; a right clapboard is arranged on the right side of the upper clapboard; a flue gas guide plate is arranged on the right side of the right clapboard; a left support plate is connected to the lower side of the left wallboard through a right support plate connecting hinge; a left locking plate is connected to the lower part of the left wallboard through a left locking plate connecting hinge; a right support plate is connected to the lower side of the rightwallboard through a right support plate connecting hinge; a right locking plate is connected to the lower part of the right wallboard through a right locking plate connecting hinge; a rear support plate is connected to the lower side of the rear wallboard through a rear support plate connecting hinge; and a rear locking plate is connected to the lower middle part of the rear wallboard through a rear locking plate connecting hinge. The multi-purpose energy-saving furnace is reasonable in structure, diverse in purpose, and good in using effect.