The present invention provides a road traffic control method based on a positioning system implemented by a road traffic control system formed by a vehicle positioning system, a pavement signal generator, a central monitor, a communication transmission system and the like. In a hazy weather state, traffic control and advance notice of vehicles approaching a spacing identifier can be performed forrunning vehicles on a highway pavement lane; remote display early warning can be timely emitted to the running vehicles when the highway pavement generates sudden excess surface water and fluid, icing, accident fire and pavement collapse and deformation; traffic control of temporarily changing a lane driving direction can be adapted; a working state of a traffic control system can be automaticallystarted or closed according to a random condition of atmospheric visibility; and purposes of assisting in safety driving and improving a highway utilization rate can be achieved, the implementation is convenient, and the practicality is high.