The invention relates to a chemical plugging agent for oilfield well repair. The chemical plugging agent for oilfield well repair comprises 60-80% of superfine cement, 3-9% of bentonite, 5-8% of calcium oxide, 5-14% of calcium carbonate, 5-7% of asbestos wool, 0.5-0.8% of fluid loss agents, 0.5-0.9% of resistance reducing agents and 0.3-1% of retarders. The plugging agent is good in flowability, safe in construction, large in plugging radius, high in compressive strength after solidification, mainly prepared from inorganic materials, high in aging resistance and long in plugging validity period.