A memory sharing method for at least a functional module and a target module is disclosed. The functional module includes at least a static random access memory (SRAM), the memory sharing method includes the steps of calculating a memory capacity of the functional module; if a total memory capacity of a module group satisfies a memory capacity requirement of the target module, allocating the SRAM of the module group, wherein the module group comprises at least one functional module; and accessing the SRAM of the functional module of the module group by utilizing the target module.