The invention provides an automatic vehicle all-terrain mode switching method and system and a vehicle. The method comprises the following steps that a driving mode of the vehicle is judged; if the vehicle is in an all-wheel drive mode, real-time road condition information and vehicle state information are obtained; a toque load diagram corresponding to the real-time road condition information andthe vehicle state information is matched according to the real-time road condition information and the vehicle state information; the vehicle is controlled to be switched to be a corresponding all-terrain mode according to the torque load diagram. According to the method, the vehicle can be switched to the proper all-terrain mode automatically according to the real-time road condition of vehicledriving, it is guaranteed that the vehicle passes the road with the bad condition smoothly, and then the driving stability and safety of the vehicle under different working conditions are improved.