The invention relates to the technical field of drilling and completion of a horizontal well and an extended reach well, in particular to a method for preventing blockage through vibration in a directional drilling process of the horizontal well. The method comprises the steps of installing a group or a plurality of groups of vibration tools on the upper portion of a drill collar and drill pipe in a horizontal well kick-off assembly and installing an anti-blocking centering device on the upper portion of the vibration tools. The method reduces the occurrence probability of sticking and blocking accidents in the drilling process, the vibration tools can generate vibration under the effect of fluid power, the vibration can be effectively transferred to nearby drilling tools, and the static friction force between the drilling tools and a lower well wall can be transformed to kinetic friction force in the sliding drilling process. The problem that the drilling tools are statically located on the lower well wall for a long time, so that drilling accidents such as drill blockage occur is solved. The shortcomings that if the drilling tools are in a static state for a long time, the adhesive force caused by the drilling tools and the lower well wall is bigger and bigger, so that the drilling tools are hard to be lifted, and even the sticking and blocking accidents occur are overcome.