As urbanization accelerates and the availability of arable land declines sharply, building-integrated agriculture (BIA) has emerged as a crucial strategy for enhancing urban food security and it also promotes the establishment of sustainable urban food production systems. This study focuses on indoor living walls (ILWs) and employs the analytic hierarchy process (AHP) and the entropy weighting method to construct a comprehensive suitability evaluation model. The model evaluates different spatial layouts across five key dimensions: indoor microenvironment, physiology of vegetable, morphology of vegetable, yield of vegetable and quality of vegetable. The results reveal that among the experimental groups, R2 was classified as suitable, with an average group score of 2.29. The remaining groups were classified as moderately suitable, with descending average scores of 1.64 for R3, 1.43 for R4, and 1.16 for R1. Based on the climatic characteristics of Hainan Province, the optimal configuration is recommended to include a north-facing room, a west-wall planting layout, and a “partial human–vegetable separation” spatial strategy, with an installation height exceeding 1.3 m.