Basing on highway bridge construction technique and management features, this paper conducts analysis and establishment to construction safety risk factor, index system, etc. of actual engineering, after using vague synthetic judgment method, analytic hierarchy process, implement research via integrated evaluation method, makes out argument to different safety risk factors, establishes bridge safety risk factor collection via method of comprehensive assessment, confirms bridge safety risk incidence value, judges matrix by using MATLAB construction vagueness, finally calculates concrete risk gradation sort, and gets highway bridge construction safety risk grade. Through practice it has proved that the construction safety risk assessment method is based on the method of quantification, can find out biggest influence factors on the safety of Bridges in engineering, and can also reduce the misjudgment caused by subjective factors. The safety of the bridge has a positive practical significance.