Abstract: Based on the summarization of Germany and Poland backfill mining,in view of coal mine building protection level and surface deformation index and oth er industry standard in China, Germany and Poland,the paper puts forward some suggestions about ground building deformation control index when backfill mining.This paper indicates that should take into account geological and mining conditions ,surface movement rule, surface protected objects口movement allowed deformation index and the flling ability in the process of the backfill mining under buildings,and design optimum calculation model of the allowed mining thickness,workface flling rate and the workface mining speed and an assessment model on reducing damage to buildings benefits of backfill mining;in addition,for the sake of ensuring the safety mining u nder buildings,avoiding excessive flling and waste flling material which increase production cost,the related research results provide the optimal design reference for b ackfill mining under buildings.