为满足实验室条件下长时间、高精度的热流密度测量要求，基于电替代测量原理研制了一种新型辐射热流计，该型辐射热流计可通过自校准的方式溯源至国际单位制单位。本文简述了辐射热流计的系统构成，结合辐射热流计的测量原理，分析并计算了辐射热流计自校准过程中9项影响量的测量不确定度和合成标准不确定度。通过与中国计量科学院所标定的标准探测器比对，计算了辐射热流计的不确定度，最后根据实验数据及分析结果为该型热流计的优化设计提供了参考。实验结果表明：辐射热流计的相对标准不确定度优于0.26%，与标准探测器的归一化偏差为0.60，验证了不确定度评估结果。实验结果将为辐射热流计下一阶段的研制提供有效参考。

In order to meet the requirements of long and highly precise heat flux measurement under laboratory conditions, a new radiative heat flux meter was developed based on the principle of electrical substitution measurement. The radiative heat flux meter can be traced to the International System of Units through self-calibration. Firstly, the system structure of the radiative heat flux meter is briefly described. Combining with the measuring principle of the radiative heat-flux meter, the measurement uncertainty of nine uncertainty components and their combined standard uncertainty in the process of radiative heat-flux meter self-calibration are analyzed and calculated. Then, the uncertainty of a radiometric heat-flux meter is verified by direct comparison with a standard detector calibrated by the National Institute of Metrology of China. Finally, according to the experimental data and analysis results, this paper provides a reference for the optimization design of the heat-flux meter. The experimental results show that the relative standard uncertainty of the radiative heat-flux meter is better than 0.26%, and the normalized error is 0.60, which verifies the validity of the uncertainty evaluation results. The experimental results will guide the development of radiative heat flow meters in the next stage and further improve its performance.