The invention relates to a hydrophobic polymer material surface hydrophilicity improving method. In order to solve the problem that material surface hydrophilicity is unendurable in the current blended technology, amphipathic microgel containing thermosensitive core and non thermosensitive core is taken as hydrophile modification ingredient in the invention, and surface hydrophilization modification is carried out on hydrophobic polymer material by casting method and melt blending extrusion method respectively. (1) The casting method includes: dispersion liquid of the microgel and hydrophobicpolymer solution are blended, the blended even dispersion liquid is casted into a film in a mold, and solvent is removed, thus obtaining a polymer film. (2) The melt blending extrusion method includes: dry microgel and hydrophilic polymer particles are blended and then put into a rotor internal mixer to be mixed for a short time at certain temperature; the material is crushed into particles afterdischarging, is extruded into sheet or wire by an extruder and forms film by a hot press. The invention has the advantages of easy technique and reliable treatment effect without a complex device andcan effectively improve the surface hydrophilicity of the hydrophobic polymer.