The invention relates to pest prevention and control of plants, and concretely relates to a method for preventing and controlling thrips in the seedling stage of tobacco. The method comprises the following steps: 1, pretreatment: selection and building of a seedbed in a leeward sunningdale and uptake place, and thrip prevention and control of the environment surrounding the seedbed; 2, seedling stage management: placement of one cup of a predacious mite mixture in the center of every square meter of a seedling tray, monitoring of the population density one time every 3 days, and uniform spreading application of the predacious mite mixture on tobacco seedlings one time at a spreading application concentration of 2000/m<2> when the thrip population density exceeds 1/plant and less than 2/plant, wherein the predacious mite mixture is a 50 ml mixture containing a carrier wheat bran and an alternative prey Amblyseius cucumeris; and 3, timely spraying application of an systemic insecticide one time when the thrip population density exceeds 2/plant, and immediate placing of one cup of the predacious mite mixture in the center of every square meter of the seedling tray after the spraying application. The method has a source control effect on the thrips and propagated tomato spotted wilt.