When calculating the reference crop evaportranspiration by use of meteorological factor,there are multiple correlation phenomenon between each meteorological factor. The phenomenon can result in distorting and destabilizing the built regression model,and reduce predictive precision.Taking Weili county in north region of Tarim basin of Xinjiang as example,the paper adopted partial least-square regression to set up ET0 model.By use of the principal component analysis and typical correlation analysis,it took method of component extract to solve the interactive correlation among meteorological factors.The built ET0 model got better effect.