Disclosed are a polymer electrolyte membrane having high flexibility, high ionic conductivity, and excellent mechanical durability, a method for manufacturing same, and an electrochemical device comprising same. The polymer electrolyte membrane of the present invention comprises a polymer electrolyte material, wherein the polymer electrolyte material comprises: an ion conductor having an ion-exchange group; and an organic compound which binds to the ion-exchange group via an ionic bond or a hydrogen bond, thereby allowing the polymer electrolyte material to have an ionic crosslink structure or a hydrogen bond crosslink structure.