Objectives: The COVID-19 pandemic has been a public health hazard since 2020. Preventive measures taken in mainland China and Hong Kong to control the spread of COVID-19, including quarantine, could potentially affect people's physical and mental health. Methods: We used a snowball sampling method to investigate the experience of people in mainland China and Hong Kong using AI chatbots during the COVID-19 pandemic to obtain information on mental health related to COVID-19, the current situation, and the multi-dimensional experience of using AI chatbots. The people who participated in the survey were residents aged 18-75 in the 2 areas. Results: The effective response rate of the questionnaire was 98%. Concerning demographics, 91.1% of the target group were 18-55 years old. The most important sources of information for the respondents were WeChat and Web pages. There was no difference between Hong Kong and mainland China in terms of access to COVID-19-related mental health information (??²=0.59, p=.444), and no difference shown in access to information by gender (??²=0.01, p=.942). There was no difference in age group (??²=2.97, p=.594) and was not related to whether respondents were in the provincial capital city area (??²=0.62, p=.429). Age groups “<18 years old” and “56-65 years old” were related to giving a higher (4 or 5) score to AI text questions answering chatbot (p=.030), and there is a positive relationship between the satisfactory of AI text question answering chatbot and that of AI voice question answering chatbot (R²=0.8074, p=.038). Conclusion: There is no significant difference in the use of all-in-one AI platforms in mainland China and Hong Kong, and both have large market potential in the field of AI services for mental health. This platform is suitable for people of all ages in both regions. The results of this study provide forward-looking guidance for our team to develop robots based on an all-in-one AI platform.