The invention provides a method for detecting the humoral immunogenicity of autologous CART cells. According to the invention, autologous T cells, which are not modified by CAR, of a testee are used as negative control target cells, autologous CART cells, which are modified by CAR, of the testee are used as target cells for detection, and the reactivity difference between the detected serum sample of the testee and the two target cells is determined through comparison through a flow cytometry, so that whether the anti-CAR antibody exists in the detected serum sample of the testee or not is judged; and the method not only can help a clinician to screen a CAR transformation method which is not easy to cause generation of an anti-CAR antibody for a patient before CART treatment is carried out on the patient, but also can be used as an etiological detection means for dynamically monitoring CART treatment failure possibly caused by induction of the anti-CAR antibody in CART cell treatment, so that CART cells play the maximum treatment effect.