The utility model relates to a combing machine coiler trumpet mouth, the internal shape of which is a trumpet-shaped pipeline, the top part of the pipeline is a conical straight pipe with the length a which is equivalent to 8mm to 20mm and the conical degree of 1:20, the diameter b of the big end of the conical straight pipe is equivalent to Phi 34mm to Phi 40mm, the tilt angle Alpha of the section of the conical straight pipe is equivalent to 15 degrees to 25 degrees, the back end of the conical straight pipe is a section of conical bending pipe with an angle Beta which is equivalent to 40 degrees to 60 degrees and the conical degree of 1:20, the central line of the conical bending pipe is a section of arc, the radius c of the arc is equivalent to R45mm to R55mm, the deflection distance e of the center of circle of the central line of the conical bending pipe and the center of circle of the bottom circle is equivalent to 30mm to 40mm, the diameter d of the bottom circle is equivalent to Phi 79mm to Phi 81mm, the deflection distance f of the central line of the conical straight pipe and the central line of the bottom circle is equivalent to 15mm to 20mm, one side of the bottom part of the pipeline on the center of circle of the bottom circle is provided with a gap, the shape of the gap is similar to a triangle, the surface of the gap and the inner side surface of the pipeline have smooth transition, and the deflection distance k of the central line of the gap and the central line of the bottom circle is equivalent to 4mm to 8mm. When the combing machine runs at high speed, the combed cotton strips are smooth, trim and have no hanging knot; furthermore, the utility model can reliably realize the fully automatic strip breaking function during the positioning parking and cylinder changing.