The invention discloses a multifunctional height gauge, comprising a base, a stand column, a combined type sliding seat, a leveling instrument, a bi-direction sliding seat, a detecting instrument, a leveling instrument contact arm, a leveling instrument rotation locking unit and an angle dial. The bi-direction sliding seat is installed on the leveling instrument and can slide left and right on the leveling instrument. The detecting instrument which is vertical to the leveling instrument is installed on the bi-direction sliding seat. The angle dial is installed on a mounting board of angle dial. The end of the leveling instrument is provided with a threaded fixing rod, which is connected with the combined type sliding seat by passing through the hole between the angle dial, the mounting board of angle dial and the leveling instrument rotation locking unit and is locked tightly by rotating the leveling instrument rotation locking unit. The height gauge of the invention can measure the related size between two points between any angle lines in the plane parallel to the stand column and the related size between two points on any two planes vertical to the stand column. The assembly and the disassembly are convenient and rapid.