Abstract: According to the actual field data in Shanghai Precision Agriculture Demonstration Base，this paper analyzes the relation between the soil nutrient and the rice yield with the main composition method．The results show that the relation between the yield and the soil nutrient such as the total nitrogen (N)is positive correlation．Among them the yield reaction is sensitive to the content of phosphor(P)in soil while the pH and the salt have negative correlation with the yield．Further analysis of the main composition method shows that among the main composition the available N has the main function． In the sour alkali characteristics，the pH shows the character of sour alkaline of soil most obviously．Absolute error of soil nutrient-paddy rice yield model that is established with the main composition analytical method is 406．5kg／hm²．and the relative error is 4．88％．so the result is good．