The invention provides a highway early warning system based on pluviometers, and the system comprises a plurality of pluviometers which are arranged along a road, display screens cooperating with the pluviometers, and control subsystems cooperating with the pluviometers. The pluviometers are set at certain intervals along a highway, and are used for monitoring the rainfall information of each place. The control systems are used for obtaining the safety running speeds of the vehicles based on the rainfall information. Each two display screens serve as one group, and display the safety running speed calculated through the rainfall information obtained by one pluviometer. Each group of display screens are disposed on opposite highways, and are respectively located at the downstream sections of the corresponding pluviometers. The system can automatically obtains the safety running speeds of vehicles under the rainfall according to the size of the rainfall.