Based on the description of windmilling start and Starter start,the Start time and Ignition time between them were compared and analyzed in this paper. By researching, we know: 1) The differences between windmilling start time and Starter start time mainly depend on the step before releasing starter. Because of the high acceleration of Starter, engine can be started in a shorter time. As the flight speed increases, the effect of Starter start decreases. The starter start time gradually approaches the windmilling start time. 2) The difference between their Ignition time mainly depends on preparation period of ignition. The starter requires longer ignition time. With the increasing of flight speed, the Starter Ignition time gradually approaches the windmilling ignition time.This study can provide reference for engine start system design and engine airstart flight test data analysis and troubleshooting.