The research on meteorological and hydrological elements data of Hotan prefecture in Xinjiang nearly 40 years shows that the annual average temperature in Hotan prefecture is on the rise; while the precipitation in Hotan River basin presents increasing trend; the average relative humidity presents decreasing trend and the increasing trend of sunshine hours is inapparent, the evaporation capacity is on the decline. The impact of climate change in Hotan prefecture on engineering of farmland water conservancy has advantages and disadvantages. The projects of farml and water conservancy should be reasonable planned so that they can better play role under the premise of ensuring safety.