The invention relates to a loop carrier roller mounting base and a method for controlling the loop outlet strip steel deviation by applying the loop carrier roller mounting base. The mounting base comprises a foundation base body, a pressing block and a U-shaped base body; a mounting groove with the top being open is formed in the foundation base body; the U-shaped base body is embedded into the mounting groove; an opening of the U-shaped base body is upward; the pressing block is detachably fixed to the top of the U-shaped base body; a mounting structure for fixing a shaft head is formed between the pressing block and the U-shaped base body; threaded through holes are formed in the left side wall and the right side wall of the mounting groove, and jackscrews matched with the threaded through holes are arranged at the left side wall and the right side wall of the mounting groove; and jackscrew holes are formed in the positions, corresponding to the threaded through holes, of the U-shaped base body. The method comprises the following steps of firstly, manufacturing and installing a loop carrier roller device capable of correcting deviation, then judging the deviation direction of strip steel, reversely adjusting the vertical line of a loop carrier roller according to the deviation direction of the strip steel, sequentially adjusting the carrier roller and observing the effect soas to achieve the purpose of correcting the deviation. According to the loop carrier roller mounting base and the method, the requirement on the installation precision is not high, the maintenance load is greatly reduced, the maintenance time is greatly shortened, and therefore the labor efficiency is improved.