Provided is high-performance nanometer lead-free solder paste and a preparation method of the high-performance nanometer lead-free solder paste. The high-performance nanometer lead-free solder paste comprises, by mass percentage, 80-90% nano-tin alloy powder, 1-3% of a nano-tin alloy protective agent and the balance rosin no-cleaning flux. The preparation method of the high-performance nanometer lead-free solder paste comprises the following steps that a nano-tin alloy precursor compound is prepared firstly, then the nano-tin alloy powder is prepared, the obtained nano-tin alloy powder and the nano-tin alloy protective agent are mixed, a mixture and the rosin no-cleaning flux are added to a reaction kettle with a stirrer and are fully mixed, and finally the product is obtained. The preparation method is simple and suitable for industrial production, and the prepared nano-tin alloy is uniform in size and small in particle size range. By the adoption of the nanometer solder paste, the surface activity of the nano-tin alloy is kept under the storage condition, and the nanometer solder paste can well adapt to the requirement of the ultrafine pitch component package.