Efficient blocking agent for drilling fluid as well as preparation method and application of efficient blocking agent

The invention relates to an efficient plugging agent for drilling fluid and a preparation method and application thereof in the field of petroleum drilling. The efficient blocking agent for the drilling fluid comprises the following components in parts by weight: 10-50 parts of calcium carbonate; 3-20 parts by weight of active fiber; 8 to 30 parts by weight of vermiculite; and 5-25 parts by weight of mica. A plugging formula is formed on the basis of a bridging material, the temperature resistance of the obtained efficient plugging agent for the drilling fluid can reach 200 DEG C, and the high-pressure-bearing requirement of a high-temperature stratum can be met. Calcium carbonate, active fibers, vermiculite and mica at all levels form a plugging layer with high adsorption capacity, the plugging layer is high in strength, good in temperature resistance, long in lasting time and acid-soluble, and the plugging operation in a reservoir meets the reservoir protection requirement. 本发明涉及石油钻井领域的一种钻井液用高效封堵剂及其制备方法和应用。