The invention discloses a method for evaluating long life of a component. The method comprises the following steps of: analyzing characteristics, an application platform and an application environment of the component; initially determining a stress level and sensitive parameters of a test; determining an application sequence of stress factors, responding to an analytical method for the sensitive parameters, and determining test equipment; performing an official test, namely recording sensitive parameter values of a component accelerated life test at certain time intervals to display changes of the sensitive parameters of the component accelerated life test along with time; performing graphical analysis by using graphic software, and selecting the best accelerator model and lifetime forecasting model; and verifying whether the models are valid, if so, evaluating the long life of the component, otherwise, redetermining the parameters. The method has the advantages of short test period, low testing expenses, general applicability, scientificity, no need of a preset model, suitability for small increments and capability of evaluating the long life of components adopting new technology and having long life.