The invention discloses a tobacco-rice rotation integrated fertilization method including the following steps: (1) fertilization in tobacco season: performing soil preparation and fertilizing a base fertilizer with N:K2O being 1:4-5; (2) tobacco straw returning to the field: picking tobacco and returning tobacco straws to the field with a rotary cultivator; (3) fertilization in paddy rice season: fertilizing urea. The method breaks a conventional fertilization method under a tobacco-rice rotation mode. In the situation that the total nitrogen application rate and potassium application rate are equal in whole year, the base fertilizer with N:K being 1:4-5 is applied in the tobacco season, and with combination of straw returning to the field and application of the urea instead of a potassium fertilizer in the paddy rice season, complementary effect in nutrient absorption of the two crops, tobacco and paddy rice, is utilized better, so that the method not only increases potassium content in the tobacco and improves quality of tobacco, but also considers growth of the two crops, tobacco and paddy rice, in a two-season rotation manner at the same time, thereby guaranteeing yield of rice and achieving high-effective utilization of the potassium fertilizer.