Abstract: A serious non-conformance in the support and hunger design was found during the construction stage in a nuclear power project. In the view of quality management, the origin for the non-conformance is that the design process was not controlled properly and the design result was given without validation. Several experiences are summarized, such as the enhancement of the management level for various leaders and quality consciousness for all staff, the improvement of process management and training scheme, and paying more attention to the communication with the purchaserand the informationization construction in the design work, to ensure the traceabilit of the design and development.