Abstract: Adopting the full implementation plan ＂3414＂,research in the impacts that the single, double and three factors of N,P,K and interaction on the development progress and agronomic characters were done.Under these experimental conditions,N_2P_2K_2, N_1P_2K_1 and N_1P_2K_2 made buckwheat ripe earlier so that the threat of frost damage was decreased. And reproductive growth will be 1~2 days in advance. Both single fertilizer and cooperation of N, P, K fertilizer can achieve the effects of increasing plant height, stem diameter, number of effective branches, number of main stem section and internode length within certain amounts. However, excessive fertilizer will inhibit these agronomic characters.