The present invention discloses a symmetrical well-defined structure comb-shaped amphiphilic polymer and a super hydrophilic modified polymer hollow fiber film. The polymer main chain is polyphosphazene comprising alternate nitrogen and phosphorus atoms, each structural unit of the polyphosphazene main chain is respectively connected with a hydrophobic chain alkyl secondary amine and a hydrophilic chain end amino polyether side group, and the structure is shown as formula (I). The fiber film is a hollow fiber film containing the polymer. The invention also discloses a method for preparing the polymer and the fiber film. By hydrophobic interactions between the amphiphilic polymer side hydrophobic chains and the hydrophobic polymer film material, comb-shaped amphiphilic polyphosphazene is stably attached to the surface of the polymer film hole, and the hydrophilic chain can effectively improve the polymer hollow fiber separation membrane surface hydrophilicity and anti pollution performance, and improves the separation efficiency. The polymer has good biological compatibility and neutral degradation degradability, and is non-toxic.