The invention relates to a multifunctional ruler for teaching. The multifunctional ruler comprises a left supporting rod and a right supporting rod. A chalk sleeve is arranged at the lower end of the left supporting rod. A supporting point is arranged at the lower end of the right supporting rod. The upper end of the left supporting rod and the upper end of the right supporting rod are rotatably arranged on a connecting block. Angle scales are arranged on the surface of the connecting block, and a vertical sliding groove is formed in the position, between the left supporting rod and the right supporting rod, in the connecting block. A movable block is arranged in the sliding groove. Scales are arranged in the surface of the left supporting rod and the surface of the right supporting rod respectively, and index lines used in cooperation with the angle scales on the surface of the connecting block are arranged at the upper end of the left supporting rod and the upper end of the right supporting rod respectively. Rotatable adjusting rods are arranged in the positions, in the connecting block, of the left supporting rod and the right supporting rod respectively. The other ends of the two adjusting rods are arranged on the movable block. The multifunctional ruler can be used for drawing circles, can be used as a straight ruler, a right angle ruler and a protractor, and is simple in structure and convenient to use.