The invention discloses an anti-cracking and anti-seepage multifunctional reinforcing agent, which is prepared by mixing the following active ingredients in parts by weight: 10-15 parts of polyacrylonitrile staple fiber, 18-24 parts of ground hydroxylapatite, 5-10 parts of perfluorooctane sulfonate, 25-35 parts of JF-6 type early-strength water reducing agent, 12-18 parts of sodium polyacrylate, 5-10 parts of ground furan daub, 3-6 parts of dimethyltetradecylamine oxide, 18-26 parts of SC-11 type polycarboxylate superplasticizer, 10-15 parts of refining slag, 4-8 parts of sodium pyrophosphate, 3-5 parts of pentaerythrityl distearate, 5-8 parts of sodium N-methyl-N-oleyl taurate, 6-12 parts of aluminum borate whisker, 5-10 parts of polyethylene glycol, 7-11 parts of amino silicon oil, 2.5-4.5 parts of zinc plamitate, and 4-6 parts of auxiliaries. Compared with the common reinforcing agent, the anti-cracking and anti-seepage multifunctional reinforcing agent is faster and more thorough in reaction, and faster and higher in strength increase; the wear resistance, durability, anti-cracking property and anti-seepage performance of the concrete can be obviously enhanced; the anti-cracking and anti-seepage multifunctional reinforcing agent also has the water-reducing, early-strength and entraining functions, and is stronger in adaptability to various concretes, and wide in application prospects.