The invention discloses an ultraviolet therapeutic instrument for dermatology, and the therapeutic instrument comprises a pedestal. The upper surface of the pedestal is fixedly provided with a telescoping rod, and the upper end of the telescoping rod is provided with a shaft seat. The interior of the shaft seat is provided with a cross rod, and the right end of the cross rod is fixedly provided with a side plate. The right side surface of the side plate is fixedly provided with a supporting plate. The therapeutic instrument is simple in structure, and is convenient to use. The telescoping rod can adjust the height of the whole therapeutic instrument, and the cross rod can adjust the horizontal positions of a light shield and lamp tubes. The therapeutic instrument can achieve the effective irradiation of a skin tissue with a disease. The bending degree of the light shield can be changed according to the adjustment of the position of a nut, so that the light shield roughly accords with the contour line of the skin tissue, and the distances between the lamp tubes below the light shield and the skin are consistent. A first distance sensor and a second distance sensor provide data support for the control of a stepping motor, thereby enabling the ultraviolet light to be uniformly distributed to the skin, guaranteeing the uniform and controllable radiation dose, and facilitating the treatment of a skin disease.