The invention provides a copper alloy bar for a high-strength corrosion-resistant wear-resistant valve element. The cooper alloy bar is characterized in that the copper alloy bar comprises, by weight,0.04-0.2% of Si, 0.25-0.6% of Mn, 0.1-0.4% of Sn, 0.06-0.2% of Ni, 0.7-1.3% of A1, 0.1-0.25% of Fe, 83-87% of Cu, 0.01-0.1% of lanthanum and strontium rare earth, and the balance Zn and inevitable trace impurities. The preparation method comprises the following steps of burdening and smelting; refining and removing impurities; degassing; adding lanthanum and strontium rare earth; carrying out horizontal continuous casting; drawing and extending a casting blank; peeling twice; and carrying out light pressing and straightening to obtain a finished product. The copper alloy component is scientific and reasonable in component ratio, and the prepared copper alloy has good machining performance and casting performance; and meanwhile, the alloy is high in strength and good in corrosion resistance and wear resistance, and can be applied to the manufacturing of the valve element of ocean engineering; the preparation process is simple and easy to operate; and the horizontal continuous casting is adopted, so that cracks caused by thermal stress are avoided, and the hot extrusion cracking problem of the casting blank is solved.