The level assessment on the ecological risk early warning and the simulation on evolutionary trend can provide reliable auxiliary decision making for the ecological risk management. Taking into account the Driving-Pressure-State-Impact-Response model, this paper establishes an index system for ecological risk early warning to quantitatively analyze the temporal and spatial differentiation characteristics and evolution trend of ecological risk in Chongqing Municipality, using the normal cloud model and the set-pair analysis method. The results demonstrate that:(1) from 2013 to 2019, the ecological risk value of Chongqing presented a "rise-decline" fluctuation trend, and the comprehensively ecological risk was ranked as heavy warning level, while the comprehensive ecological risk value decreased from 0.295 to 0.278, denoting that the ecological environment had been improved. (2) There were five evolutionary trends of ecological risk in Chongqing:decreasing, unchanged, increasing-decreasing, decreasing-increasing and always increasing, accounting for 39%, 16%, 5%, 21% and 24% of all regions, respectively. (3) The ecological risk transferred to ward two orientations in Chongqing. From 2013 to 2016, the medium-alert, light-alert and no-alert risk areas continued to spread to the northeast, southeast and west of Chongqing, which intensified the spatial differentiation of ecological risks; whereas from 2016 to 2019, the high-alert risk areas were concentrated in the east, suggesting the little change in the ecological risk distribution pattern. (4) The simulation results of evolution trend revealed that 13 counties, accounting for 34% of all areas, would experience the declining ecological risk and subsequently improving ecological environment in Chongqing in the future; additionally 25 counties, accounting for 66%, would maintain the deterioration of ecological environment to small extent. The combination of ecological risk classification with early warning evolutionary trend can contribute a scientific basis to urban ecological risk management.