The invention discloses a masonry structure transformation method and an underpinning structure for masonry structure transformation. The transformation method includes the steps that (10) constructional columns are reinforced, i.e., the constructional columns at the two ends of a wall to be demolished are reinforced with latticed columns, and the lower ends of the latticed columns are in tight contact with a foundation; (20) underpinning beams are arranged, steel box beams are arranged on the two sides of ring beams of the wall to be demolished, the two ends of each steel box beam are fixedly connected with the latticed columns at the two ends of the wall to be demolished correspondingly, and the side faces of the steel box beams are fixedly connected with the ring beams of the wall to be demolished; and (30) the masonry work wall is demolished, i.e., a wall body to be demolished under the ring beams is demolished. The underpinning structure comprises the latticed columns (1) and the steel box beams (2), the latticed columns are arranged around the constructional columns (4) at the two ends of the wall to be demolished (3) in a reinforcing mode, the steel box beams (2) are arranged on the two sides of the ring beams (5) of the wall to be demolished, the two ends of each steel box beam (2) are fixedly connected with the latticed columns (4) at the two ends of the wall to be demolished (3) correspondingly, and the side faces of the steel box beams (4) are fixedly connected with the ring beams (5) of the wall to be demolished. According to the masonry structure transformation method and the underpinning structure for masonry structure transformation, construction is simple, and investment is little.