The invention discloses a positioning device for X-ray testing equipment. The positioning device is characterized by comprising a base (3), a supporting platform (6) which is installed on the base (3) and capable of sliding along the base, a lifting device which is arranged on the supporting platform (6) and can rise and fall, and a clamping component arranged on the lifting device. The positioning device is simple in structure and low in cost, installation and fixation of an X-ray machine and an imaging board can be achieved quickly, the relative positions of the X-ray machine and the imaging board can be correspondingly adjusted according to tested equipment conveniently, and the positioning device is suitable for application and popularization.