Method and device for setting preliminary alarm lights at traffic merging point

The invention discloses a method and a device for setting a preliminary alarm signal light at a traffic merging point. The method comprises the following steps: step 1, judging whether a preliminary alarm signal light needs to be set or not according to the saturability of an approach and the distance from a merging point (3) to an intersection (4); step 2, if the judging result is yes, respectively setting a main road preliminary alarm signal light (1) and an auxiliary road preliminary alarm signal light (2) at the merging point of a main road and an auxiliary road; step 3, monitoring the traffic flow in real time after the preliminary alarm signal lights are arranged, and dynamically adjusting opening and closing of the signal lights according to the comparison of the traffic flow and apreset threshold; and step 4, associating the signal lights of the main road and the auxiliary road with the signal light (5) of the intersection (4) when the signal lights are in a normal working state. According to the meth