Abstract: In order to solve the problem of soil personalized fertilizer application, the authors tested N, P and K content from 10 soil samples in northern China by fast testing method and conventional method. The results showed that both of the two methods had fine correlation, and the correlation indexes reached 0.966, especially the correlation index of K reached 0.99, which also showed significant differences. Curve regression equation was set up, which could be used in fast conversion to get the content of conventional method to guide fertilization. The fast testing method was fast and convenient, there was no need for the staff to prepare the reagent, the instrument could be operated easily without the involvement of professional experimenter and had low cost for detection, it could be widely used by grassroots technical staff.