A hierarchical and flexible method for setting a memory reliability level to implement a memory access mechanism for different running object types and different reliability levels. The method implemented by the memory device includes receiving reliability level information of a running object of a processor sent by the processor; establishing a mapping relationship according to the reliability level information of the running object; receiving an access request sent by the processor; and accessing data of the running object and error-tolerant code of the running object according to the access request and the mapping relationship.