The invention relates to a high-strength and high-conductivity rare earth copper alloy for contact lines and a preparation method thereof. The rare earth copper alloy is composed of chromium, zirconium, zinc, titanium, silver, copper, rare earth elements and inevitable impurity elements, wherein during preparation, a Cu-Zr intermediate alloy and a Cu-rare earth intermediate alloy are prepared at first, and then the Cu-Zr intermediate alloy and the Cu-rare earth intermediate alloy are smelted and subjected to mould casting with copper, zinc, silver and titanium to form a cast ingot, the cast ingot is subjected to hot extrusion to obtain a bar billet, the bar billet is subjected to solution treatment, the treated alloy is subjected to drawing deformation, and then subjected to aging treatment to prepare the high-strength and high-conductivity rare earth copper alloy. The conductivity, elongation, strength and softening temperature of the alloy disclosed by the invention can be greatly improved; the machining performances of the alloy are remarkably improved; the manufacturability of the alloy can be changed, thus benefiting refining, degassing and microalloying; and the requirements of a material for the industrial field of contact lines on the performances of copper alloys can be met well. The alloy disclosed by the invention is simple in preparation process, short in process flow, high in strength, good in conductivity and excellent in hot-working property.