Peanuts are highly nutritious but pose a significant risk of triggering food allergies. While heat treatment can reduce the allergenicity of many foods, it may also alter their structure, potentially impacting detection results. This study employed double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and lateral flow immunochromatography (LFIA) to evaluate the allergen Ara h 3 following heat-moisture treatment. DAS-ELISA achieved a detection limit of 39.06 ng/mL, with inter-plate and intra-plate coefficients of variation below 3.05 % and 6.79 %, respectively, and recovery rates ranging from 78.48 % to 90.93 %. LFIA, with a detection limit of 1.6 μg/mL, demonstrated high sensitivity, stability, and no cross-reactivity with other proteins. Both methods were effective in detecting peanut-processed products, with heat-moisture treatment significantly reducing Ara h 3 antigenicity, making them valuable tools for assessing desensitization in food production.