Given the framework of incremental mesh simplification bascd on edge collapse, the paper proposes a mesh simplification algorithm using an improved approach for measuring simplification error. The algorithm uses edge collapse to simplify the triangle mesh and maintains surface error approximations using c-error for the faces which have changed after edge collapse and d error for the faces which become degenerated after edge collapse. Also, we report some results using a variety of computer graphics models, which can show that the algorithm can achieve the desired simplification effect.