Abstract: A material performance test facility simulating the inside temperature and atmosphere environment of the high temperature gas-cooled reactor was built by the Institute of Nuclear and New Energy Technology of Tsinghua University. All kinds of tests under high temperature (≤1600 ℃) carbon reducing environment could be conducted in the facility. During the test, strong disturbance caused by the central large current heating was found to be imposed on the thermocouple signals. A high-frequency random fluctuation with the amplitude of 50 ℃ was superimposed on the original temperature signals. Based on the NI high-speed synchronous acquisition technology, the signal interference analysis test was carried out and the interference source and path were determined. Finally aimed at its self pattern of the interference signal, an anti-interference software method was proposed to solve the thermocouple signal fluctuation phenomenon and successfully guarantee the accurate temperature control and measurement in the test zone.