The invention discloses a folding blackboard. The folding blackboard comprises a main blackboard, wherein an upper magnet is installed above the main blackboard; a lower magnet is installed below themain blackboard; the right side of the main blackboard is connected with a right blackboard through a right hinge; the left side of the main blackboard is connected with a left blackboard through a left hinge; an upper right magnet is installed at the upper right part of the right blackboard; a lower right magnet is installed at the lower right part of the right blackboard; an upper left magnet isinstalled at the upper left part of the left blackboard; a lower left magnet is installed at the lower left part of the left blackboard; the right side of the main blackboard is connected with a right wall; an upper right wall magnet is installed at the upper right part of the right wall; a lower right wall magnet is installed at the lower right part of the right wall; the left side of the main blackboard is connected with a left wall; an upper left wall magnet is installed at the upper left part of the left wall; and a lower left wall magnet is installed at the lower left part of the left wall. According to the folding blackboard disclosed by the invention, 1/4 of each of the two sides of the blackboard is folded, and the four magnets are arranged at four corners and capable of fixing the blackboard onto the wall. If the blackboard is not enough for being written by a teacher, the two sides of the blackboard can be folded, combined towards the center, and then spliced into one blackboard for being written. In this way, a great effect is achieved.