The invention discloses a lead-in device of the branch mechanism for a six-stage branch well used in the well completion of an oil-field oil-gas multi-stage branch well, which consists of a branch connecting mechanism, a main pitshaft pipe column, a main pitshaft lead-in guiding shoe, a branch pitshaft lead-in guiding shoe and a branch pitshaft pipe column, wherein the branch connecting mechanism is made of expandable alloy materials; the branch pitshaft lead-in guiding shoe is provided with an oblique opening structure; the main pitshaft lead-in guiding shoe is provided with an eccentric structure; the branch connecting mechanism is welded with the main pitshaft pipe column; the main pitshaft pipe column is fastened with the main pitshaft lead-in guiding shoe by dowels; the branch pitshaft lead-in guiding shoe is fastened with the branch pitshaft pipe column by the dowels; and the branch connecting mechanism is welded with the branch pitshaft pipe column. The device solves the problem that the four-stage branch well in the prior art cannot realize water conservancy tightness and mechanical integrity of windows. The lead-in device can be widely used in the well completion of the oil-field oil-gas multi-stage branch well.