Abstract: In order to solve the supply of K at 75 days after transplanting and increase the content of K in tobacco leaves, pot and field experiments were carried out to study the effects of the organic inorganic mixed fertilizers on the K apparent release characteristics and the effects of different application methods on yield and quality of tobacco leaves, as well as the content of total K and sensory quality. The results showed that 4 kinds of organic inorganic mixed potassium fertilizers of different organic matter content could slow down the apparent release rate of K, with the treatment group of organic matter content 18%, K₂O content 24% had the best effect. Field experiments were carried out in 3 regions to verify the 30% organic inorganic mixed potassium fertilizer and screened method. The results showed that:the treatment group was significantly better than control in K content of tobacco leaf, yield, output value and sensory quality. K content of tobacco increased by 11.43%-25.87% in the three locations. The 30% organic inorganic mixed fertilizer could effectively slow down K release, significantly increase K content and improve inherent quality of tobacco Leaf.