The invention relates to a new method capable of quickly reducing center temperature of postmortem pig carcass through two-stage cooling. The method comprises the following steps of: in the first stage, placing a pig half carcass, which is slaughtered, cut into a half and washed ultrasonically to reduce bacteria, into a large-scale vacuum cooling machine; starting a refrigerating system and a vacuum pump of the vacuum cooling machine; performing vacuum cooling for 20 to 30 minutes under the vacuum degree of more than 610 Pa, so that the center temperature of the half carcass is reduced to about 20 DEG C quickly; taking out from the vacuum cooling machine; and entering the second stage to perform conventional air cooling, namely cooling in an air cooling storage for 2 to 16 hours under the conditions of temperature of between 0 and 4 DEG C, air speed of about 0.5 to 1 m/s to reduce the center temperature of the half carcass to 0 to 4 DEG C, wherein water supplementation (spraying 1 to 3 percent of cold tap water at the temperature of between 0 and 4 DEG C) is necessary before and after vacuum cooling and in the vacuum cooling process so as to make up for water loss of the pig half carcass in the vacuum cooling process. In the treatment method, the vacuum cooling method adopted in the first stage has the effects of effectively reducing cooling time, saving energy consumption, reducing occurrence rate of pale, soft and exudative (PSE) pork, improving processing efficiency and reducing microbial pollution, so the method is safe, sanitary and environment-friendly.