The invention belongs to the field of transformers, and particularly relates to an auxiliary equipment for detecting the compactness of a transformer iron core, which comprises a base, the outer surface of the right side of the base is rotationally connected with a detection mechanism, and a display mechanism is arranged on the left side of the detection mechanism. According to the auxiliary equipment for detecting the compactness of the transformer iron core, by arranging the bottom plate and the top plate, when the equipment is used, the iron core of the transformer is placed in a gap between the top plate and the bottom plate, and the iron core of the transformer is mostly an EI iron core and can be exactly clamped in the EI-shaped clamping grooves in the bottom plate and the top plate, so that in the process of gradually stacking the iron core upwards, the base plate moves along with the iron cores, it is guaranteed that the iron cores cannot incline or deviate in the vertical direction, a set of iron cores are perpendicular to the upper surface of the base all the time, errors during detection are reduced, and the problems that when traditional clamping equipment fixes the iron cores, loose iron cores are prone to skew and deviate, and measurement errors are increased are solved.