The invention discloses an environmentally-friendly drilling fluid with high plugging performance. The drilling fluid comprises 2-6% of bentonite, 0.3-0.5% of sodium carbonate, 0.3-0.5% of an inhibitor, 0.2-0.5% of a coating agent, 0.1-0.3% of xanthan gum, 2-8% of a filtrate reducer, 2-5% of a plugging agent, 1-4% of calcium carbonate, 0.5-4% of a lubricant, and 25-250% of an inert weighting agent; and the nano plugging agent is formed by compounding of a product prepared from carbon spheres coated with AlOOH, acrylamide, N-isopropylacrylamide and hexamethylenetetramine and a vinyl acetate-ethylene copolymerization emulsion. The environmentally-friendly drilling fluid has the characteristics of high plugging performance, high lubricating performance, a good rheological property, strong ability of carrying rock debris, and friendliness to environments, and the environmentally-friendly drilling fluid is specially applied to environmental sensitive areas regions.