In order to explore the evolution law of extreme precipitation events during the process of urbanization in Kunming, the temporal and spatial evolution characteristics, severity and urban effect of extreme precipitation events in Kunming from 1960 to 2017 were quantitatively analyzed based on the percentile method, Mann-Kendall test, R/S analysis and other methods. The results show that from 1960 to 2017, the extreme precipitation in Kunming showed no significant increasing trend with a rate of 0. 24 mm/a, while its occurrence rate, contribution rate and intensity all showed increasing changes. The distribution of precipitation was uneven between night and day. The extreme precipitation in the main urban area and the downwind area of the city had obvious high value areas. From 1960 to 2017, the enhancement coefficient of urbanization to annual extreme precipitation was 1. 16, which indicated that the effect of urbanization on increase of precipitation was obvious, and the effect tended to intensify. The urban effect of Kunming was not obvious in the slow development period, while the mean value of extreme precipitation difference between urban and suburban areas increased by 57. 04% in the rapid development period with the urban effect being prominent. The extreme precipitation severity index and the index difference between urban and suburban areas showed continuous increasing trend, which indicated that the severity of extreme precipitation and the effect of urbanization on it will continue to intensify.