An efficient mapping information management technology for non-volatile memory is disclosed. When a host requests to access data of a first logical address, a microprocessor of a controller of the non-volatile memory loads a first sub-mapping table from the non-volatile memory to a volatile memory. The microprocessor loads hierarchical pointer tables related to the first logical address into the volatile memory. Among the hierarchical pointer tables, each higher-level pointer table lists non-volatile memory physical addresses of lower-level pointer tables. A non-volatile memory physical address of the first sub-mapping table is obtained from a first pointer table according to a first index, for the microprocessor to load the first sub-mapping table from the non-volatile memory into the volatile memory for mapping information of the first logical address, and the first pointer table is in the lowest level among the hierarchical pointer tables loaded in the volatile memory.