The invention relates to calcium-added nail protecting liquid. The calcium-added nail protecting liquid is prepared from 48-53 of water, 23-28 of polyurethane, 16-20 of acrylic acid/VP cross-linked polymer, 5.3-7.9 of propylene glycol, 0.6-0.8 of fatty alcohol polyoxyethylene ether type emulsifier, format-I compounds, 0.1-3.95 of calcium gluconate and other auxiliaries. No photoinitiator, volatile oil solvent, benzene, formaldehyde, ethyl acetate or DBP type harmful substances exist in the formula, and the liquid has the advantages of being environmentally friendly, capable of being rapidly dried, free of illumination and stable in film formation. The liquid can nourish nails and help to eliminate the symptoms of nail unevenness and fragileness caused by the lack of calcium; the effect of healthily protecting nails is achieved while nails are beautified.