The invention provides a magnetic refrigeration system of a multistage magnetic regenerator. The magnetic refrigeration system comprises a magnetic body, a flow channel (2), a hot end heat exchanger (51), a cold end heat exchanger (52) and the multistage magnetic regenerator (1), wherein the multistage magnetic regenerator (1) comprises n magnetic regenerators (101,102,...1n) which are connected in series, n is an integer which is greater than 1, the first end of the multistage magnetic regenerator (1) are connected with an inlet and an outlet of the hot end heat exchanger (51) respectively through two flow channels (21, 22), and the second end of the multistage magnetic regenerator (1) are connected with an inlet and an outlet of the cold end heat exchanger (52) respectively through two flow channels (25, 26). The magnetic refrigeration system of the multistage magnetic regenerator has the advantage of high efficiency, the refrigeration loss caused by irreversible factors during backheating can be reduced, the refrigeration efficiency of fillers of the regenerators is fully improved, the internal heat transfer efficiency of the regenerators can be effectively improved, the large temperature span is established, and the enough refrigeration output of the system is guaranteed.