Objective To study the difference of eating habits between patients with ankylosing spondylitis (AS) and the healthy controls, and to explore the role of diet as an environmental factor in the pathogenesis of AS. Methods A total of 123 AS patients and 120 matched healthy volunteers were enrolled in the present study from Jul. 2014 to Apr. 2015. The single factor and multivariate analysis were used to compare the differences in eating habits between the patients with AS and the healthy volunteers. According to the Bath ankylosing spondylitis disease activity index (BASDAI), AS patients were divided into active disease group (BASDAI> 4 points) and non-active disease group (BASDAI≤4 points), and the relationship between disease activity and eating habit was studied. The patients were also divided into HLA-B27 positive group and HLA-B27 negative group to study the effects of diet and HLA-B27 interaction on the incidence of AS. Results There were significant differences between the AS patients and the healthy volunteers in eating taste tendency, staple food structure, average daily high cholesterol food, daily soy products, and smoking and drinking frequency(P<0.05). Multivariate analysis showed that spicy taste, moderate daily intake of soy products and moderate drinking were the protective factors for AS, and smoking was an independent risk factor for AS (P<0.05). The disease activity of AS was not related to the eating habits. There were significant differences between HLA-B27 positive patients and the healthy volunteers in eating taste tendency, soy intake, smoking and alcohol consumption(P<0.05, P<0.01). Conclusion The dietary components may be an important environmental influencing factor of AS. HLA-B27 may interact with eating habits in their influence on the pathogenesis of AS.