This national survey study aimed to explore the teachers' perceived impact of COVID-19 on the development of preschoolers in urban China. 22,466 preschool teachers were randomly sampled from 11 provinces of urban China and surveyed online. First, descriptive statistics found that the teachers perceived the highest improvement in preschoolers' social skills and interpersonal relationships, whereas the least improvements in emotion and psychological health. Second, latent profile analysis generated three profiles: (1) Low Level; (2) Medium Level; and (3) High Level. Among the patterns of demographic factors, those in the profile with development stagnation or regression were most likely to be younger children in Western China public preschools. Finally, regression analyses indicated that parental involvement could significantly predict their children's developmental changes. The findings imply an increased focus on preschoolers' emotional and psychological health support. To cope with the crisis, family-preschool collaborations are needed.