The invention discloses a super-short vertical waveguide coupler with a high manufacture tolerance. The coupler is composed of an upper waveguide, a spacing layer and a lower waveguide in the vertical direction. In the spreading direction, the vertical coupler is divided into an input area, a coupling area and an output area. In the coupling area, the width of the upper waveguide decreases gradually, and the upper waveguide is divided into front, middle and rear segments; and in the front and rear segments, the width of the upper waveguide are contracted rapidly, and the middle segment is a mode transfer segment. The thickness of the spacing layer between the upper and lower waveguides is reduced to increase a coupling coefficient, and the length of the coupler is reduced; and in the middle segment of the coupling area, a proper upper waveguide width successively-decrease rate and a proper length are set, so that when the width of the upper waveguide deviates due to limitation of the practical manufacture precision, the mode of the upper waveguide can be still transferred to that of the lower waveguide, and the high manufacture tolerance is realized.