Good foot care knowledge and behaviour are very important to prevent the occurrence of diabetic foot, but there are few reports on the foot care knowledge and behaviour of older people with diabetes in the community. The purpose of this study was to understand the foot care knowledge and behaviour of older people with type 2 diabetes in Beijing community, and analyse its influencing factors, so as to provide reference for further intervention. We investigated 254 older people with type 2 diabetes in Xinjiekou community, Beijing, including their general information, chronic complications, foot care knowledge and behaviour. The results showed that the average scores of foot care knowledge and behaviour were 73.38 ± 12.25 and 49.70 ± 8.70, respectively. Multiple stepwise regression analysis showed that the factors affecting the total score of foot nursing knowledge of older people with diabetes in community were gender, duration of diabetes and whether they had received foot nursing education (p < 0.05). The factors influencing the total score of foot nursing behaviour were gender, duration of disease, whether they had received foot nursing education and peripheral vascular disease (p < 0.05). In conclusion, the knowledge of foot care of older people with diabetes in community is in the middle level, and the foot care behaviour is not optimistic. Community healthcare workers can improve patients' knowledge of foot care and improve their compliance with foot care behaviour through foot care health education. At the same time, we should pay more attention to men, those with a shorter duration of diabetes and diabetic patients with peripheral vascular disease to reduce the occurrence of diabetic foot.