According to the time series of hydrological data of Xi’an station from 1951 to 2011, the paper used Mann Kendall method and Morlet wavelet to analyze change trend of Xi’an’s temperature and precipitation. The results showed that the average temperature of Xi’an increases as a whole, a two rise in temperature from 1959 to 1963 and 1995 to 2011 are obvious, and the trend of precipitation decrease is no obvious and show frequent and large fluctuations. The main cycle of temperature and precipitation decadal variability is 25a and 12a, the main cycles of temperature and precipitation interannual variability are both 6a.