Traditional environmental efficiency evaluations based on DEA methods generally neglect that the inputs，desirable outputs and undesirable outputs are possibly discrete variables．Therefore，they cannot pre_x005fcisely address the integer practical variables，which consequently affect the validity of the evaluations．This paper extends the super efficiency SBM model based on mixed-objective integer DEA and builds a new superefficiency SBM model which considers both integer constraints and undesirable output variables． Searching algorithm is applied to solve the new model and Bootstrap method is further used to amend the results in an application．By measuring the distance between each optimal integer point and the evaluated decision making u_x0002_nit，the shortest one，i. e.，Pareto improvement direction，can be found．This model provides a more applicable tool for environmental efficiency evaluation．