Guide signs have a very good guiding effect on people"s outgoing, and good design of guide signs can improve the driving efficiency of drivers. The amount of sign information at nodes in the road network will affect the driver"s ability to read sign information, thereby affecting the overall traffic efficiency of the whole network. Therefore, by introducing the amount of guidance sign information from nodes as a penalty coefficient, the cost of the road segment is calculated, and a guidance path planning model between ODs is established. Combined with the A * algorithm, the entire road network is traversed to obtain the optimal guidance path between ODs. By adding guidance information on the guidance path, the coherence of guidance sign information between ODs is improved, guiding drivers to make path choices better, and reducing traffic pressure in the road network. And select the area from the railway station (point O) to the People"s Hospital (point D) in Qingyang City, Gansu Province for practical application and analysis.