The invention provides a method for improving hardness and strength of high-purity gold, which is characterized by comprising the following steps: A) putting a commercial high-purity gold block in a graphite crucible with high purity, strength and density, putting the graphite crucible into a vacuum smelting furnace, heating under the high vacuum condition of 10-3Pa grade of vacuum degree until the high-purity gold block is melted, and slowly cooling to the room temperature in the vacuum smelting furnace to obtain the high-purity gold base metal original workpiece; and B) putting a high-purity gold original workpiece into a mold, under the liquid nitrogen temperature condition of -196DEG C, unitizing the falling kinetic energy of a gravity drop hammer to enable the original workpiece to generate rapid compressive deformation, so as to obtain the high-purity gold block body with high purity, strength and density. Compared with the prior art, the invention has the advantages: 1) the purity of the high-purity gold is not changed; 2) the method is simple, and the equipment is cheap, low-temperature and rapid deformation is realized by using the liquid nitrogen and the gravity drop hammer, and the hardness and the strength of the high-purity gold are improved; and 3) the method is suitable for improving the hardness and the strength of the fine gold, thousand pure gold, pure gold, gold of different purities and gold alloy.