The invention relates to a traffic conflict quick identifying method based on the pupil diameter of a driver, and belongs to the technical field of traffic engineering. The method includes the steps of: data collection, including collecting pupil diameter data of the driver by an eye tracker; data processing, including removing blink data and performing wavelet decomposition to generate pupil diameter data to be matched; template pupil diameter analysis, including adopting the pupil diameter within a traffic conflict time period as a template and performing Fourier transform to generate template frequency spectrum data; setting GSA initial conditions, defining fitness values, and setting GSA iteration ending conditions and traffic conflict identifying process ending conditions; GSA calculation; process iteration; result output. The invention first proposes the traffic conflict identifying method adopting the pupil diameter of the driver as the index, and adopts and improves the GSA search algorithm, thus being capable of quickly identifying the traffic conflict.