The convergence of drifts for mining the hanging wall ore was measured by use of Model WRM-3 convergence meter during transfer from open-casing to underground mining in Daye Iron Mine.On the basis of the measured results,the authors identified some factors affecting the convergence of drifts.In this paper,the principle of grey prediction and residue difference examination of its prediction effect is briefly introduced.Combining with the field practice of Daye Iron Mine,the application of grey models in the prediction of deformation trend is presented out.The authors consider that grey prediction is applicable in underground engineering.