Based on the evaluation system of astronomical infrared detectors， the performance of two InGaAs NIR detectors， liquid nitrogen-cooled and thermoelectric-cooled， was tested using a modified "photon transfer curve" tests method. The measured value is 83 e^-， which is much higher than the nominal value of 15 e^-； the high and low conversion factors of NIRvana are 1.25 ADU/e^- and 0.097 ADU/e^-， respectively， and the readout noise is 105 e^- and 380 e^-； the measured value of dark current of NIRvana at the high conversion factor step is 415 e^-/s， which is about twice of the nominal value. The theoretical estimate of the signal electron number of the Yunnan Observatory two-meter ring telescope at 1.565 μm solar magnetic field measurement is about 8800 e^-， and the NIRvana-LN detector signal-to-noise ratio is 70 under the measured dark current of 4.06 e^-/s， image exposure time of 20 ms， and readout noise of 83.59 e^-.