Nucleic acid testing is a critical means of combating COVID-19. However, the overcrowding caused by large-scale nucleic acid testing increases the risk of virus infection and challenges the existing health supply chain. Aiming at alleviating overcrowding, this paper studies the determinants of people’s choice of testing sites. The results show that physical distance and decision information exert positive influences, whereas the impact of urgency is not significant. The results of a specially designed computer simulation program verify the empirical study. It was also found that information disclosure does not affect the overall completion rate of the nucleic acid testing and the average time taken to complete the testing. However, it aggravates overcrowding in queues. The findings overturn the previous view that information disclosure improves social efficiency. This paper acts as a reference for governments dealing with overcrowding during large-scale social mobilization.