The invention relates to a separation device which adopts the pressurized continuous high-precision distillation for extracting trichlorosilane and method thereof, including a low-boiling-point compound separation tower, a high-boiling-point compound separation tower and a hydrogen or argon pressurizing system, wherein, the feeding materials enter the middle part of the low-boiling-point compound separation tower after passing by a raw material pre-heating heat exchanger, the low-boiling-point products are separated at the tower top of the low-boiling-point compound separation tower, and a trichlorosilane forerunning product discharge pipe line at the tower bottom is connected to enter the middle part of the high-boiling-point compound separation tower. The high-purity trichlorosilane product is obtained at the tower top. The purity of the purified trichlorosilane product by the process reaches more than 99.999 percent, wherein, the content of boron, phosphorous, iron and other impurities is all less than 10ppb, the content of the impurities of the mixture of the trichlorosilane and other low-boiling-point compounds and high-boiling-point compounds is less than 5.0ppm, the recovery rate of the process is larger than 98.0 percent, meanwhile, the pressurized continuous high-precision thermal coupling distillation and separation technology of the entire invention has simple process flow and lower energy consumption.