In recent years, due to the progress of internet and mobile technology, citizen science has been rapidly developed and popularized. Citizen participation in scientific projects is becoming an emerging trend of scientific research, which is of great significance for improving citizens’ scientific literacy and promoting civic education. Based on the Web of Science core collection database, this paper carries out basic analysis on the number of annual papers and subject categories of citizen science project cases abroad from 2000 to 2019. The visualization software Citespace is used to draws the knowledge map in order to analyze the number of publications from different research institutions, authors, citations, and keyword clusters. Characteristics of the cases are found based on the analysis above. Finally, recommendations are proposed on the future of China’s citizen science project case studies, from the three aspects of research fields, institutional platform and citizen participation.