Abstract: This paper points out that the integrated problem of entrance on ramp control, mainline control and corridor control must be studied in order to solve traffic jam of freeway effectively. The integrated control framework of entrance ramp metering, mainline control and corridor control based on Multi-agent is proposed after the characteristics of Multi-agent and traffic flow process in the freeway are analyzed. As the key problems, short term traffic flow forecasting and the communication between the agents are stated.