Online financing projects allow users to post comments on projects including various topics in different stages. As a typical user generated content, due to the dynamic generation of comments on online financing projects, user will produce different text topics among various stages. Based on the comment text of online financing projects, this study analyzes the dynamic topics evolution in the online comments, considering both the time and topic factors. Using 5,405,498 comments from Kickstarter as corpus, dynamic topic model is employed, and the online comments are divided into two stages: antecedent stage and posterior stage. The experimental results show that, in the antecedent stage, the topics such as social promotion and content of the project are the mainstream. In the online comments after the financing, namely, posterior stage, there are huge differences in topics. The topics are distributed among the progress inquiry, fund usage, product discussion, etc. This phenomenon may be due to the differences between project schedules and reality. This study shows the dynamic changes of online investor’s concerns, which provides a channel for the analysis of online investment opinions.