The invention discloses an organic salt used as water lubricating additive and a preparation method thereof. The molecular formula of the organic salt is [Li(B)] A, wherein [Li(B)]<+> represents a cation, B represents a nonionic surfactant, and A<-> represents anionic tetrafluoborate, hexafluorophosphate, trifluoromethanesulfonate or di(trifluoromethylsulfuryl)imino group. The nonionic surfactant is Tween, polyethyleneglycol octyl phenyl ether, polyalkaneneglycol, polyethyleneglycol, fatty alcohol polyethenoxy ether, an emulsifier OP-10, polypropylene glycol, polyether, polyethyleneglycol fatty acid ester, fatty amine polyethenoxy ether or castor oil polyethenoxy ether. The invention also discloses a preparation method of the organic salt. The organic salt has stabler and lower friction factor and better lubricating and antiwear resistance, does not need ion exchange, separation, purification or any other complex step in the synthesis process, and thus, is low in preparation cost.