On the basis of the thought of system and fuzzy decision, the grey system theory is applied to solve the problem of UERR (underground engineering reinforcement and reconstruction), and index system of UERR is built. According to the strengthening of multiple targets optimization models of UERR a Pareto optimum concourse of many satisfied solution is got. The grey fuzzy optimal selection model of the Pareto solution is established, and the corresponding GA is given. The example shows that it can obtain the useful conclusion from the model.