The invention provides a method for realizing integrated charging gateway in on-line charging system, which is characterized by including steps of: step 1, configuring interface module needed to be loaded; step 2, configuring data link between communication net element; and step 3, configuring interface service information, inputting output data of designed data link to designed interface module,and inputting output data generated after operation by designed interface module into designed data link. The aim of the invention is to provide a method for realizing multithreading treatment technology configuration based on message with reasonable structure, good expandability and good reliability.