Abstract: The methods to maintain the capability of testing laboratories included effective internal and external monitoring of the laboratory, ensured the normal operation of basic factors such as personnel, equipment, methods, and environment, and continuously improving control levels. For abnormal results in daily testing and capability verification, comprehensive analysis and judgment should be conducted on the influencing links of the experimental process, to identify the reasons for abnormal results, and taken timely improvement measures to ensure the long-term maintenance of laboratory capabilities.