The invention relates to a geosteering method for dynamic modeling during drilling and dynamic adjustment of the track in the process of horizontal well drilling of oil drilling. According to the solution, computer software is used, mutual multi-well comparison is carried out on target layer hierarchical data, target layer result structural maps, earthquake target layer pickup and multilateral well target layer data, and a plane difference algorithm is used, so that a target layer initial three-dimensional geological model is built; a two-dimensional geological model is extracted according to the track of a horizontal well which is being drilled, the direction of a drill bit is adjusted according to the spatial relation between the drilling track and the two-dimensional geological model, the vertical depth between the top and the bottom of the portion, arranged on each key point, of a target layer is obtained during drilling according to the electronic logging characteristics or the gasometry characteristics of special key points encountering a drill, such as a marker layer, a landing point, a bottom outlet, a bottom inlet, a top outlet, a top inlet and a special layer in the target layer, and the thickness uniformity principle, the three-dimensional geological model is adjusted, a two-dimensional geological model is extracted according to the track of the horizontal well which is being drilled, and the hole deviation angle of the drill bit is modified according to the dip angle provided by the two-dimensional geological model; the process is repeated, and it is ensured that the drilling direction of the drill bit is kept to be within the controllable range all the time. The hit rate and the drilling-encounter ratio of well drilling are improved, the drilling cycle is shortened, and drilling efficiency is improved.