The invention relates to a health assessment method for a 500 kV high-voltage power transmission line in the mountain land occurrence environment. According to the health assessment method, with a 500 kV high-voltage power transmission tower where geology hidden dangers exist as the research core, internal factors for generating the geology hidden dangers of the power transmission line are described as external factors of tower footing bearing capacity and tower footing rock mass quality assessment, and based on a multi-factor combination control theory, relations between all the influence factors and the health state of a tower footing are described; the change of mountain land geomorphic features is expressed as the important factor for influencing a wind-induced vibration response, and wind speed, the wind-induced vibration response and the wind-induced vibration coefficient are needed by quantitative description in the process of health assessment on the power transmission line; a fine three-dimensional infinite element model is used for simulating a high-voltage power transmission tower system existing in the mountain land occurrence environment, and a high-voltage power transmission line health assessment analysis platform of multi-factor cooperative control is constructed with the tower footing geology hidden dangers and wind loads as main control factors, so that the quantitative index of the health state of the power transmission line is determined.