A repair circuit includes: a plurality of redundant memory cells, each redundant memory cell being configured with a state signal; and a repair module connected to the plurality of redundant memory cells and configured to determine target memory cells from the redundant memory cells based on the state signals and repair defective memory cells through the target memory cells. The target memory cells are in one-to-one correspondence to the defective memory cells. The repair module can repair, at each of multiple repair stages, different defective memory cells, the plurality of redundant memory cells being shared at the multiple repair stages.