Abstract: Based on the finite element theory，the treatment effect analysis of retained goaf in iron deposit was put forwards from the main factors of the safety evaluation on filling mass at retained goaf and the control of surface deformation.Taking an example of a typical mine，and based on analysis of the filling mass′s displacement and stress field′s regularity after filling of gob，the safety factor at sensitive points of filling mass was calculated with Mohr-Coulomb criterion.The surface deformation control effectiveness with filling or no filling after excavation was analyzed through comparison.The filling effect in the iron ore deposits was comprehensively analyzed.The conclusion was made as follows:The vertical displacement of the filling body is 5 times of horizontal displacement.The total filling mass is in the state of compression，and its stress value is less than the compression strength.The safety factor at the sensitive area of the horizontal filling mass is about 5，which satisfies the requirements；The surface deformation after filling governance is reduced to 50%，so the filling effect is remarkable.The treatment effect analysis model of retained goaf established plays a guiding role in implementing the filling scheme and in treating the similar mines on the premise of ensuring the strength of filling mass and the rate of supporting pit roof.

Key words: Iron deposit, Retained goaf, Treatment effect, Analysis method