The invention discloses the application of 2-propynyl-2-hydroxyalkyl ether in a nickel leveling agent and a polishing agent as a nickeling intermediate and a preparation method of the 2-propynyl-2-hydroxyalkyl ether nickeling intermediate. An ether compound, the 2-propynyl-2-hydroxyalkyl ether is generated from the addition reaction of propiolic alcohol, propylene epoxide and ethylene epoxide in the invention. Compared with the propiolic alcohol, the chemical stability of the 2-propynyl-2-hydroxyalkyl ether is good and the 2-propynyl-2-hydroxyalkyl ether is not easy to decompose; besides, an electroplating nickel plate is softer and has better brightness and leveling, wide bright scope, quick turning to be bright and high production efficiency if the 2-propynyl-2-hydroxyalkyl ether is used in nickeling liquid, the dosage of the polishing agent is reduced, the consumption of nickel is less and the cost is greatly reduced, thus not only being applicable to ordinary simple work pieces but also can gain satisfactory effects even for complicated work pieces.