Since the first case of genetically modified (GM) food appeared in the world, the debate about its risks has followed. Supporters believe that GM food has advantages of rich nutrition, high crop yield and long freshness period, while opponents think that there are many hidden dangers in its safety. This debate will affect consumers' cognition of GM food, and then affect their actual consumption behavior. Therefore, this paper completes a randomized survey of 500 consumers in Shanghai and found that: firstly, GM food is not fully popular and about 5% consumers have not been exposed to GM food; secondly, risk perception plays a suppressive role in both GM food acceptance and purchase intention.