Abstract: In order to study the rule of synergism of goaf system in the process of dymanmic evolution , 3D- finite element method is used. Based  the practioce of a specific project，the synergism of roof-pillarsystem in goaf is studied， and the safety rate，plastic zone and stress fieM distribution of roof pillar systemin each simulation scheme are obtained , the mechanical response of cooperative process ing mode d voidsystem is explored.From the concept of ynergism ,to guarantee the subsequent ore which is mined safe-ly，the mining environment reoonstnuction of waste filling technology is proposed to proceed with the origi-nal environmental modification of ore body. 'The results of FEM prove that collaborative development isconditional. When the roof span is 15 m，20 m and 30 m, the corresponding coondinated pillar stnucturedimensions are 3 m，4.5 m and 6 m. 'The index of limiting exposed awea are respectively 1 000 m3 ,1 600 m'with the rod of goaf system being as marble and basalt. 'The concentration d stress intensifieswith existing way to mine follow-up ore.'T'he maximum ternsion stress of rod reaches 3.496 MPa, which isinferior to the peak strength d surrounding rock and the safety rate d 0.924 is far below critical state.When the ore envirorment is transfomed by waste filling，the maximum tension stress reduces to1.655 MPa，and the safety ratio rises to 1.229.'The stress field and safety ratio are improved and thesynergism of system can be confirmed during the mining prooess of subsequent ore.

Key words: ｏｐｅｎ-ｓｔｏｐｅｍｅｔｈｏｄ, ｒｏｏｆ-ｐｉｌｌａｒｓｙｓｔｅｍ, ｍｉｎｉｎｇｅｎｖｉｒｏｎｍｅｎｔｒｅｇｅｎｅｒａｔｉｎｇ, ｓｙｎｅｒｇｉｓｍ, ｎｕｍｅｒｉｃａｌｓｉｍｕｌａｔｉｏｎ