The invention discloses an oil-well corrosion-inhibition salt inhibitor and a preparation method thereof. The oil-well corrosion-inhibition salt inhibitor is obtained by mixing a substance A, a salt inhibition main agent and a salt inhibition auxiliary agent in a mass ratio of (5-30):(5-20):(1-10), and adjusting pH to 6-8, wherein the substance A is prepared by reaction of 1-halogenmethyl naphthaline and quinoline at 130 DEG C-150 DEG C. Corrosion-inhibition rate of the corrosion-inhibition salt inhibitor can reach over 85% under acid conditions such as a high temperature (120 DEG C) and a high degree of mineralization (20*10<4> mg/L), so that a pipe has no point corrosion on surface and has salt inhibition rate of over 90%. After being used, the agent can be decomposed into an organic phase and an organic phase, wherein the inorganic phase can be treated with sewage in output liquid, and the organic phase is in a state of suspension and can be directly separated.