[Objective] This paper reveals the change of uers’ interests in the crowdfunding projects and analyzes the dynamic evolution of their online comments on these projects. [Methods] First, we retrieved 497,936 online comments on 6,537 technology-related projects from Kickstarter as corpus. Then, with the help of LDA model, we analyzed the topic evolution of these comments. Finally, we obtained the dynamic evolution model of the topics with the help of cosine similarity. [Results] In the initial stage of financing, the comments were mainly on basic project information. Then, the comments focused on return of investments and product information. In the final stage, these comments were on the shipping issues. For successful projects, the topics developed from project description to waiting time for products and deliveries. For the failed projects, the comments gradually evolved into the possible relaunch and prospect of a new project. [Limitations] We did not distinguish the project categories, which need to be analyzed in the future. This paper only examined the reward based crowdfunding model, which also needs to be expanded. [Conclusions] This article analyzes reviews of online crowdfunding projects and expands the application of LDA in the field of crowdfunding, which provides practical suggestion for platforms, project sponsors and investors.