Objective To understand the knowledge, attitude and practice (KAP) of residents in the Beijing-Tianjin-Hebei region about Food-medicine substances (FMS), in order to provide a basis for improving the related policies and regulations as well as guiding residents to consume FMS scientifically. Methods From August to December 2020, a survey on the KAP of residents aged 18 and above in Beijing-Tianjin-Hebei region about FMS was conducted by using online electronic questionnaires with the convenience sampling method, analyzed the proportions of different responses, compared the differences between groups with the chi-square test and Fisher's exact probability method, and analyzed the frequency of FMS purchased and consumed by the word frequency. Results The 1119 respondents in the Beijing-Tianjin-Hebei region accurately recognized 23.6% of FMS, and more than 97.0% of them were willing to learn about the knowledge either actively or passively. The top three sources of knowledge about FMS were television and radio, social media platforms and software, doctors and experts, etc. More than 90.0% of the respondents believed that the names of FMS used and the intake limits should be marked on the food labels. More than 75.0% of the respondents scored ≥6 on their understanding of the concepts of FMS, as well as their trust in the knowledge of FMS, recognition of their health-improving effects, and understanding of their functions. 56.1% of the respondents were consumers who regularly purchased food products with FMS, and 95.9% of the respondents purchased FMS for the purpose of improving their physical health. The main purpose of 95.9% of the respondents was to improve their health. Supermarkets, e-commerce platforms and pharmacies were the main ways for respondents to purchase FMS. When purchasing food products, respondents were mainly concerned about the quality and whether they contained ingredients and functions of FMS. The three types of FMS most frequently purchased and consumed by survey respondents were yam, wolfberry and jujube. There are statistically significant differences in the cognition of FMS among people with different education levels, attitudes towards FMS among people of different genders, ages, education levels, and occupations, and consumption behaviors towards FMS among people of different ages, regions, education levels, and occupations (P < 0.05). Conclusion The knowledge of residents in the Beijing-Tianjin-Hebei region about FMS was insufficient, but they had a positive attitude towards the understanding of FMS, and their willingness to consume and demand for popularization of scientific information was very high. In the future, it is necessary to increase the popularization of FMS related information and demand research, innovate publicity ways and means to actively promote FMS, and guide residents to consume FMS in a scientific and reasonable manner.