Abstract: Food allergy is a serious public health problem which affects 5% of adults and 8% of children in the world, and the prevalence is still rising. Because there is currently no cure for food allergy, it is still the best choice for patients that strictly avoiding substitution or contacting with allergen food. The detection of allergen in food is closely related to food production, labelling and risk management, which is one of the critical steps in guarantee of food safety. Therefore, it is critical for protecting sensitive patients to develop rapid, sensitive, accurate, reproducible and standardized methods. Compared with traditional detection methods, biosensor, as an emerging type of multi-disciplinary cross-fusion technology, takes the advantages of high sensitivity, highly automated, easy operation, fast response, less sample usage and so on. It has been widely used in the detection of food allergens. In this article, we elaborate and review the detection of food allergens by optical biosensors, electrochemical biosensors, and piezoelectric immune biosensors from the principles, advantages, disadvantages and applications. Finally, we look forward to the future development trend of biosensor in the detection of food allergens and provide a reliable analysis method for rapid on-site quantitative detection of food allergens.