The invention discloses a quick passage guidance system of an ambulance, which comprises a medical end server, a traffic end server, an onboard MCU, an onboard GPS module, an onboard display screen and an onboard wireless module, wherein the traffic end server plans a plurality of paths between a hospital and a help seeker on a GPS map according to address information of the help seeker and the hospital, and finds out the path with an optimal traffic condition as a preferable path based on data of a speed measurement device and an image acquisition camera; finally, the traffic end server transmits data of the preferable path to the medical end server; the medical end server transmits the data of the preferable path to the ambulance; the onboard MCU in the ambulance controls the onboard display screen to generate optimal path map navigation. The system can exert a real-time navigation effect for quick passage of the ambulance in a first aid process, allows the ambulance to avoid congested roads and increases a first aid success rate.