Based on the data of phenological stages of dormant, flowering and fruiting of yellow peach and the contemporaneous meteorological elements in Fengxian from 2009 to 2018, the daily averaged relative humidity and minimum daily relative humidity during the flowering and fruiting periods of yellow peach from 1980 to 2018, the main meteorological disaster factors affecting the flowering and fruiting of yellow peach in 2016 and the characteristics and influence of relative humidity during flowering and fruiting periods in 39 years are analyzed by contrast and mathematical statistic methods. The results show that in 2016, from the beginning of flowering to the flowering period of yellow peach, fine weather lasted for 6 days, and the minimum daily relative humidity was less than 30%, and the average relative humidity from 09:00 to 20:00 every day was less than 50%. As a result, a large decrease was induced in fruit setting that year. The average relative humidity and the average minimum relative humidity in the flowering period of yellow peach showed a downward trend since the 1980s, and both mutation years are in 2000. The probability of lowhumidity weather in late March and early April was high so that low wet weather increased the risk of extreme lowhumidity disaster in the flowering period of yellow peach. The beginning of flowering period was significantly positively correlated with the first day of 5d sliding average temperature being greater than 10 ℃ from 2009 to 2018， based on which the partial least squares regression equation is established and verified. It is concluded that the model performs well in dealing with lowhumidity weather.