Abstract: We compares the impact of strip-partial mining on overlying strata and surface under different mining and remaining ratio conditions by using numerical simulation, and presents a strip-partial mining parameter determination method based on the key strata theory. Research shows that the width of mining strip mainly influence the scope of breaking overlying strata and the width of remaining strip control the superimposed effect of mining; the more of the key strata fracture is, the greater of the surface subsidence is; through limiting the width of mining strip to reduce the number of broken key strata can effectively reduce surface subsidence. Therefore, the principle of parameter determination is that the width of remaining strip must meet the strength requirements and the width of mining strip must meet requirements for controling key strata.