The invention provides a device and a method of measuring transmission line split conductor corona noise in a near field. In the device and method, a net-shaped metal cage formed by a metal net is made into an electromagnetic shield unit according to a principle of Faraday cage, and the electromagnetic shield unit is used for accommodating a noise measurement instrument, then the electromagnetic shield unit fixing the noise measurement instrument is put in a near field area of a noise source sound field so as to measure noise data. Compared with the prior art, the device and the method maximize a ratio of tested split conductor corona noise and environment noise, so that the measurement result is slightly affected by environment noise, signal to noise ratio of measured data is improved effectively, and the measurement result is more accurate; and the noise measurement device is simple and convenient, can keep measuring split conductor corona noise online in near field, enables testersto acquire accurate noise data conveniently, and improves running stability of the system.