Four factors which are connected with effectiveness of team learning were defined, and they were motivation of knowledge learning, ability of knowledge transfer and sharing, methods of knowledge learning and system of knowledge learning respectively. Evaluation model of team learning in expressway project was established. Based on this model, weights and values of each secondary level index were determined with Delphi method. Using the weighted average method, evaluation values of four first level indexes were calculated, which were drawn in radar chart. In order to seek the worst result, radar chart should be adjusted, and final evaluation result of knowledge learning was ascertained by calculating the minimum area of polygon. Taking YR expressway project as an example for positive analysis, evaluation and result analysis of team learning was carried out.