The invention discloses a trichlorosilane rectification system, which comprises a first rectification tower, a condenser, a second rectification tower, a first reboiler, a subcooler and a second reboiler, wherein an inlet of the condenser is connected with the first upper outlet of the first rectification tower, an outlet of the condenser is connected with a first return flow opening of the first rectification tower, a first inlet of the first reboiler is connected with a first lower outlet of the first rectification tower, a first outlet of the first reboiler is connected with a first air return opening of the first rectification tower, a second inlet of the first reboiler is connected with a second upper outlet of the second rectification tower, a second outlet of the first reboiler is connected with a second return flow opening of the second rectification tower, an inlet of the subcooler is connected with a second outlet of the first reboiler, an outlet of the subcooler is connected with a second return flow opening of the second rectification tower, an inlet of the second reboiler is connected with a second lower outlet of the second rectification tower, and an outlet of the second reboiler is connected with a second air return opening of the second rectification tower. The trichlorosilane rectification system according to the embodiment of the invention has the advantages that the produced trichlorosilane quality is high, the energy consumption is low, the equipment investment is low, and the like.