The bearing support breakage of screw coal powder conveyor in power plant boiler went through four stages: axial displacement of shaft sleeve, shaft sleeve wearing by shield ring and by bearing, and the wearing of skeleton seal rings and dustproof felts by shaft sleeve. By analyzing the wearing characters of each part, the renovation structure was designed. The bearing settled style was changed from using shield ring to using locknut by designing convex sidestep on the shaft sleeve, preventing the axial from drifting. Substituting for the welding assembly, the bolt connecting between the covers and the bearing support body was selected to replace the worn sealing materials easily in dismantling and installing. Good operating effects were achieved after the renovation of the coal powder conveyor bearing support, in the screw coal powder manufacturing line of 100MW power plant boiler, there was no line vibrating, coal leaking, noising and line locking, having decreased the repairing cost greatly and insuring the safety and stable electric power producing.