The utility model provides a novel a car anticollision for hazy weather device which the main characterized in that of: including power module, ultrasonic sensor, buzzer module, control ECU, singlechip, data memory, display module. By the power module power supply, ultrasonic sensor's control end and receiving terminal are connected with the singlechip, and data memory is connected with the singlechip, and buzzer module and control ECU are connected, and the display module is connected with control ECU, and the ultrasonic sensor dress of this device is inside the preceding air -inlet grille of automobile. The utility model discloses an ultrasonic sensor can detect out current car and preceding vehicle or the real -time distance that changes of barrier accurately, show through the display module, when the distance of car and preceding vehicle or barrier be less than that the car owner sets for apart from the time, buzzer module will report to the police, the speed reduction of suggestion driver is gone slowly, avoids the emergence of traffic accident. Adopt the singlechip, data memory is favorable to the car to development electronic age completely.