The invention provides a method for realizing an asynchronous buffer with an entry occupation indication function. The method comprises: providing a universal asynchronous buffer; then adding an output port in design of the asynchronous buffer, wherein the output port is used for outputting a pointer of a buffer occupation entry based on a read clock domain; judging the quantity of entries written in the asynchronous buffer by a reading party of an asynchronous interface according to a value of the pointer; and dynamically setting a store-and-forward threshold by the reading party of the asynchronous interface as needed based on the quantity of the entries written in the asynchronous buffer.