To accelerate the construction of resilient cities in the Yangtze River Delta urban agglomeration, with the goal of facilitating the integrated and high-quality development, this study used the panel data of the Yangtze River Delta urban agglomeration from 2015 to 2021 and adopted the entropy weight-TOPSIS method, kernel density estimation, spatial Markov chains, and geodetector model to explore the spatiotemporal evolution characteristics of flood resilience and the influencing factors of cities in the Yangtze River Delta based on the pressure-state-response framework. The results show that the flood resilience of the Yangtze River Delta urban agglomeration shows a fluctuating upward trend, with the data increasing from 0.393 in 2015 to 0.441 in 2021, but the proportion of cities in the state of medium and low resilience is high. The development of regional flood resilience is uneven, presenting a polycentric situation centered at the provincial capital city, with the occurrence of polarization phenomenon. Urban flood resilience is transferred from low resilience to high resilience, and high resilience cities demonstrate a high probability to maintain their own state and have a positive spatial spillover effect on neighboring cities. Spatial heterogeneity in urban flood resilience is the result of the combined effect of multiple factors, and the interaction between factors has a double factor enhancement effect.