The utility model discloses a highway noise on -line monitoring system supervises measuring station point by two and constitutes, prison measuring station point includes pillar, lightning rod, noise appearance, car flow monitor, solar energy power supply system and communication device, the lightning rod is installed to the pillar at the top, install noise appearance, car flow monitor and solar energy power supply system on well upper portion, solar energy power supply system is used for for noise appearance and the power supply of car flow monitor, and communication device is used for supervising measuring station point's message routing and receipt, is first prison measuring station point located the trackside, apart from highway 3 5m, is second prison measuring station point located the service area, apart from highway 10 100m. Compared with the prior art, the utility model discloses be equipped with prison measuring station point at service area and highway side simultaneously, avoid the decay, can measure noise and living area noise on the spot respectively, through setting up car flow monitor, can monitor the vehicle flowrate of different time points to it is in relevancy with noise and vehicle flowrate.