The invention provides a ramp speed limiting value prompting device and method and relates to the field of traffic safety. According to the invention, the device and the method comprises steps of based on a current environment image or the current travel speed, or based on the current environment image and a road type, recognizing whether the acquired current environment image includes a ramp speed limiting identifier; then, when the current environment image includes the ramp speed limiting identifier, according to the current environment image or the current position information or the travel state information, judging whether a vehicle enters a ramp preparation state; and when the vehicle enters the ramp preparation state, generating a speed limiting value prompt corresponding to the ramp speed limiting identifier, thereby achieving precise determination of the ramp speed limiting identifier. According to the invention, through the precisely determined ramp speed limiting identifier, it is determined that the vehicle enters the ramp preparation state, and at this moment, a speed limiting value prompt corresponding to the ramp speed limiting identifier is generated, so precise speed limiting value prompting is achieved when the vehicle travels on the ramp, error judgment will not be caused and experience of the driver is improved.