The invention provides a medical micro tube extrusion forming method. The structure comprises extrusion die sleeves, limiting core rods, an extrusion rod and a sleeve ejector block. The structure is characterized in that a plurality of groups of extrusion die sleeves and limiting core rods have different sizes and specifications. By selecting the specifications of the extrusion die sleeves and thelimiting core rods, the diameter and wall thickness of output tubes are adjusted, the extrusion rod is pushed under the action of the sleeve ejector block, and medical micro tube extrusion forming iscompleted.