Abstract:The half hot repair technology for flash furnace developed by Jinlong Copper Co, Ltd was introduced in detail. The technology was used to maintain and replace bricks in triangle section under the reaction tower, the settler’s roof at the tower exit and three side-walls in front of the settler in august 2010. It took only 19 days to complete all the work. With the efficient half hot state repair technology, workload can be reduced by nearly 50% and time spent is 30 days shorter than that in cold-state repair. Good economic and social benefits are achieved.