Energy-saving system and method for purifying trichlorosilane

The invention discloses an energy-saving system and method for purifying trichlorosilane. The energy-saving system comprises a pre-separation part, and the pre-separation part is used for pre-separating input raw materials to produce light-component impurities and heavy-component materials; and the trichlorosilane separation part is used for carrying out heat pump rectification on the heavy component material, and a trichlorosilane product is extracted. And the tower top gas compressed by the tower top heat pump is used as a heat source of the condensation reboiler at the tower kettle, and energy balance of tower top condensation and tower kettle reboiling can be realized by inputting a small amount of electric power, so that the consumption of cold and hot public works is reduced, and the problem of limited energy-saving effect of a differential pressure thermal coupling rectification process in the prior art is solved. According to the heat pump rectification method, the energy-saving system is adopted, and