Chlorosilane on-line detection device and method

The invention discloses a chlorosilane on-line detection device and a method for detecting dichlorosilane in chlorosilane by using the chlorosilane on-line detection device.The chlorosilane on-line detection device comprises a feeding unit and a detection unit, the feeding unit comprises a sample pipeline, a first pipeline, a first communication valve and a second communication valve, the input end of the sample pipeline is communicated with a chlorosilane process pipeline, the output end of the sample pipeline is connected to a first interface of the first communication valve, two ends of the first pipeline are respectively connected to a second interface of the first communication valve and a second interface of the second communication valve, and the detection unit comprises a second pipeline, a chromatographic detection valve and a flash tank; the input end of the second pipeline is connected to the first interface of the second communication valve, the flash tank is arranged on the second pipeline, and t