In order to improve the durability of foamed mixture lightweight soil(FMLS), the analytic hierarchy process(AHP)and fuzzy comprehensive evaluation(FCE)were combined to comprehensively evaluate the durability of FMLS. Based on the physical and mechanical properties of FMLS, the influencing factors were selected from the point of view of preliminary design, construction technology, and operation management, and the grade classification of influencing factors was established. The comprehensive evaluation model of FMLS’ durability was established based on the target layer, criterion layer, and index layer. The weight of the lower layer relative to the upper layer was determined by the AHP, and the consistency check of the judgment matrix was conducted to prove the rationality of the distribution of influencing factors’ weight. The membership function suitable for each influencing factor was built to calculate the membership degree, and the specific method of fuzzy comprehensive evaluation is presented. Using the lightweight soil subgrade in the charging island along the S03 section of a highway in Guangdong Province as an example, its durability was evaluated, demonstrating the practicality and reliability of AHP-FCE.