The invention relates to a method for transforming a 220 kV non-excitation voltage regulating transformer body into an on-load voltage regulating transformer body. The method comprises the following steps that (1) the distances between a left iron core side yoke, a right iron core side yoke, an A phase iron core column, a B phase iron core column and a C phase iron core column are enlarged; (2) low-voltage windings are wound on the A phase iron core column, the B phase iron core column and the C phase iron core column again, high-voltage windings are wound outside the low-voltage windings, and voltage regulating windings are wound outside the high-voltage windings; (3) an upper iron yoke which is matched with the A phase iron core column, the B phase iron core column and the C phase iron core column is replaced; (4) taps are made on the voltage regulating windings, and through an on-load voltage regulating tapping switch, the taps with different directions and different numbers of turns are connected with the high-voltage windings in series. According to the method, improvement is conducted based on an existing transformer body, and replacing and purchasing of a new transformer are of no need. The no-load voltage ratio can be regulated anytime and anywhere, power outage is of no need, manpower and material resources are saved, and electricity selling benefits are increased.