A three-stage (Medusa-Polyp-Ephyra) life history model of Aurelia aurita is formulated to investigate the role of ephyra and explore the ecological effects of sea surface temperature and seawater salinity on blooms. Both theoretical analyses and numerical simulations explain the mechanisms of A. aurita blooms in specific seasons. Sensitivity analyses (SAs) characterize the key factors that affect population sizes and provide a basis for feasible and effective control recommendations. In agreement with observational data, we then summarize the interannual variation patterns in the A. aurita population in Jiaozhou Bay and generalize its distribution in the Yellow Sea. This study shows that the occurrence of strobilation, ephyra development, and degree of asexual reproduction can significantly influence the steady states of A. aurita. Moreover, the population size of medusae is sensitive to medusa mortality and strobilation. The findings provide some valuable insights into revealing the mechanisms of A. aurita blooms and explain the connection between its population dynamics and environmental factors. •MPE model characterizes the effects of temperature and salinity on Aurelia aurita.•Medusae are mainly dependent on the bottom-up supplement of strobilation.•Substrate constraint is more feasible and flexible to control Aurelia aurita bloom.•Seasonal variation mainly affects Aurelia aurita by regulating strobilation.•Quantity variance in the Yellow Sea is affected by latitude distributions.