In the component-based software development (CBSD) process, developers need an effective selecting method to search eligible component. That is how to choose the most appropriate and suited component from component library effectively. This paper proposed a new approach of evaluating component on the basis of linear comprehensive approach. We analyze a set of factors and their weights, and put forward the method of arranging components in an order after classifying in the component library. Our experiment shows the approach is better than other approaches such as subjective mind and simple linear weighting method.