In the process of mapping, cartographic generalization is one of the most technologically and intellectually challenging aspects, such as many algorithms for automated generalization of linear features have been addressed, but in reaching pleasing results they still hold many shortcomings, particularly for large-scale reduction. Hence there is an urgently important topic for study how to assist the operators in selecting appropriate algorithms to perform generalization in quantities and swiftly for digital mapping by assessing algorithms. Douglas, Li-Openshaw, Bendsimplify and Shape algorithms as examples, this research took the linear features of maps aiming at roads, coastlines and rivers into the qualitative and quantitative assessments of simplification algorithms.