In higher vacuum field, one of the main factors of affecting the degree of vacuum is the pollution of vacuum pump oil,which is mainly caused by the back-streaming of the backing pump oil. Based on the technology of semiconductor refrigeration, the semiconductor cold trap is designed. The trap can be effectively used to resist the back-streaming of oil,thereby to increase the degree of vacuum. The basic principle of a semiconductor refrigeration apparatus is:to connect it with power supply, the In higher vacuum field, one of the main factors of affecting the degree of vacuum is the pollution of vacuum pump oil, which is mainly caused by the back-streaming of the backing pump oil. Based on the technology of semiconductor refrigeration, the semiconductor cold The trap can be effectively used to resist the back-streaming of oil, thereby to increase the degree of vacuum. the basic principle of a semiconductor refrigeration apparatus is: to connect it with power supply, the