For better control of potassium picrate(KP) production,the factors affected the crystallization process of KP should be dissertated. On the basis of the introduction for spontaneous crystallization of KP,orthogonal experiments are adopted to investigate the importance level of different factors in this article. The optimized technology conditions are found: feeding time 20 min,quantities of crystal modifiers 20 ml,feeding concentration 0.4 mol·l-1.