The invention discloses high-activity rosin soldering flux. The high-activity rosin soldering flux is prepared from the following raw materials in parts by weight: 20-30 parts of rosin, 10-15 parts of phenolic resin, 5-10 parts of lactic acid, 5-10 parts of salicylic acid, 2-5 parts of citric acid, 2-3 parts of malonic acid, 10-15 parts of stearic acid, 5-10 parts of octaphenyl polyoxyethyiene, 2-5 parts of lauryl sodium sulfate, 0.5-1 part of aniline hydrochloride, 0.5-1.5 parts of zinc chloride, 1-1.5 parts of tin chloride, 0.2-0.5 part of aluminum chloride, 0.5-1 part of catechol, 1-3 parts of mercaptobenzothiazole, 5-10 parts of water, 2-5 parts of alcohol and 3-4 parts of acetone. The high-activity rosin soldering flux disclosed by the invention is not only environment-friendly in a using process, but also capable of improving the welding effect to the greatest extent.