The invention discloses an underway monitoring system, and the system comprises an underway monitoring vehicle, a vehicle-mounted computer, a positioning system, a mass spectrometer, a laser radar andan AHSA, wherein the vehicle-mounted computer, the positioning system, the mass spectrometer, the laser radar and the AHSA are placed on the underway monitoring vehicle. The positioning system, the mass spectrometer, the laser radar and the AHSA are respectively connected with the vehicle-mounted computer; and the vehicle-mounted computer is used for summarizing and displaying the data detected by the positioning system, the mass spectrometer, the laser radar and the AHSA according to the detection time. According to the invention, the underway monitoring system provided by the invention comprises the AHSA, the laser radar, the positioning system, the mass spectrometer and other detection instruments; the monitoring effect on the atmospheric environment state is more comprehensive, and the actual atmospheric pollution state of the monitoring area can be accurately, quickly and comprehensively reflected in combination with the underway route and the concentration distribution conditionof pollutants on the underway route.