Uncertainty analysis is an essential approach to evaluate the accuracy of CFD (computational fluid dynamics) calculation. CFD was used to simulate CHF (critical heat flux) in a circular tube, and a second-order PCE (polynomial chaos expansions) surrogate model was developed. This model was used to analyze the uncertainty of input parameters (such as inlet temperature, mass flow rate, and wall heat flux) on the maximum wall adjacent heat transfer coefficient and the maximum wall temperature. The results show that the PCE surrogate model developed based on using CFD-CHF (computational fluid dynamics to calculate critical heat flux) has high computational accuracy, and the wall heat flux has the greatest impact on the wall adjacent heat transfer coefficient and the maximum wall temperature, and the application of PCE surrogate model suitable for to specific scenarios effectively reduced the computational time for CFD uncertainty analysis.