Provided in the present application are a VEGFR1 antigen polypeptide comprising three polypeptides: H DEGVYHCKATNQKGSVESSAYLTVQGTSDKSN LE OH H DLKLSCTVNKFLYRDVTWILLRTVNNRTMHYSI OH and H ESGLSDVSRPSFCHSSCGHVSEG KRRFTYDHAEL OH and a use thereof for detecting plasma immunological marker VEGFR1 autoantibody. Also provided are a method of detecting plasma immunological marker VEGFR1 autoantibody utilizing VEGFR1 antigen polypeptide of the present application and a kit comprising the VEGFR1 antigen polypeptide.