Frame of lifting machine for portable transformer

The utility model discloses a frame of a lifting machine for a portable transformer. The frame comprises a base, an outer gantry frame and an inner gantry frame, wherein the base comprises left and right longitudinal arms, a front cross arm across the rear middle parts of the left and right longitudinal arms and a rear cross arm across the rear ends of the left and right longitudinal arms; the outer gantry frame comprises a pair of vertical columns fixed on the front cross arm of the base, a gantry beam across the rear sides at the tops of the pair of vertical columns and a bracket across the rear sides at the upper parts of the pair of vertical columns; the inner gantry frame comprises a pair of straight beams and a cross beam across the upper ends of the pair of straight beams; the inner gantry frame is glidingly mounted on the inner side surfaces of the pair of vertical columns of the outer gantry frame. The frame provided by the utility model can be used for keeping the lifting height of the lifting machi