Abstract: Based on the daily precipitation data in Guanghan area in recent 60 years, combined with the local economic data, the annual and seasonal precipitation trends and the periodic variation of multi-time scale precipitation time series in this area were analyzed by using the methods of univariate linear regression, cumulative distance leveling, Mann-Kendall mutation test, Morlet wavelet analysis. An economic model is introduced to study the response of county economic output to weather changes. The results show that the annual precipitation in the Guanghan region in the past 60 years shows a nearly normal distribution and an overall decreasing trend. The climate change trend rate of the annual precipitation is −22.5 mm/10 a, and the precipitation in all four seasons is decreasing. At a large time scale, Guanghan region shows an alternate trend of "more rain - less rain - more rain". In the past two years, rainfall was concentrated, and the frequency of floods and droughts increased. In addition, the annual precipitation mutation is not significant. There are 3 distinct periods, 6 a, 12 a and 28 a. The change of precipitation will significantly affect the total output of the economy, and the influence degree is as follows : the tertiary industry> the primary industry> the secondary industry. A reduction in low-intensity precipitation between 0~20 mm per day will lead to a decline in regional economic, while extreme precipitation with > 50 mm per day will not have a significant impact on the economic in the region.