As a risk-informed technique, Human Reliability Analysis (HRA) is widely applied in the Human Factors Engineering (HFE) activities of main control room (MCR) design, especially for the task analysis in the HFE, to identify the weakness of the design and the mechanisms of potential human errors. From the other side, task analysis also provides detailed sequences of human tasks, which can be used as the basis of the quantification of HRA. The paper shows how the HRA is combined with the task analysis, so as to improve both the qualities of HRA and task analysis in the HFE, and better direct the design activities to minimize the potential human errors.