The invention relates to Cu-Sn-Sb silver-free intermediate-temperature solder and a preparation method thereof. The Cu-Sn-Sb silver-free intermediate-temperature solder comprises the following compositions in percentage by mass: 8 to 12 percent of tin, 1 to 4 percent of antimony, 0.1 to 0.4 percent of phosphor, 0.05 to 1 percent of nickel, and the balance being copper. The Cu-Sn-Sb silver-free intermediate-temperature solder is suitable for braze welding of steels and coppers in the refrigeration industry, such as braze welding of compressor housing members. The invention overcomes the defects of high solder cost and poor mechanical properties in the prior art, and provides the intermediate-temperature solder having the advantages of low cost, simple preparation method, good wettability and superior mechanical properties through the tin, the antimony, the phosphor and the nickel.