DRepeated mining of remaining coal in coal mining area was an important mean to make full utilization of coal resources. However, early mining caused activation of overlying strata and prediction of mining subsidence had changed a lot, so there were greater errors in applying first mining prediction parameters right now. Therefore, change characteristics after repeated mining were analyzed on the basis of a large number of previous empirical formulas. Combining with measured data of Yangquan area, the probability integral method for predicting surface subsidence probability of incomplete repeated mining was found and this parameter had successfully predicted a working face in this area.