[Objective] Considering the disturbance to environment caused by highway construction in order to found the optimal protection measures of soil and water loss caused by highway construction was demonstrated. [Methods] Based on the comprehensive analysis of factors affecting soil erosion during the construction, a multi-level and multi-index highway construction evaluation system with respect to soil and water loss was established. Via engineering parameter analysis, a parameter, termed as SWⅡ, was introduced into the evaluation of different sections of highway. The entropy method was chosen to determine the influence degree of each evaluation index of the evaluation system. 9 preliminary sections of liangping-zhongxian highway project were chosen to evaluate. [Results] 4 sections were classified as severe loss level and as key protection areas. [Conclusion] This article verified the rationality of the evaluation system and eliminated man-made interference. This evaluation system can determine key areas of soil and water loss under highway construction in a more objective and scientific way.