The invention discloses an intelligent multisource assessment method and device for limit mileages of intelligent unmanned vehicles. According to the method, a slope energy consumption value, a temperature energy consumption value, a wind resistance energy consumption value and length index at road sections with different speeds are put forward by combining road environments, influence factors, for unmanned vehicle power consumption, of complicated road environments are quantified, and an unmanned vehicle power consumption prediction model is established; the power prediction of the method isunrelated to batteries, vehicle models and vehicle part performance, and training is carried out by the model in real time, so that the prediction result is not influenced by the using time and life of the batteries and the vehicles; and when the vehicle running speed is high, the wind resistance is the main part of the vehicle energy consumption. According to the method, different power consumption prediction models are selected according to the sizes of wind speeds, and different power consumption prediction models are used for high and low wind speeds, so that input parameters of the modelsare decreased, the calculation time is shortened, the prediction precision of the models can be improved, and the timeliness is stronger.