The present disclosure relates to a method of screening an anti-NRP1 antibody or an antigen-binding fragment thereof by use of patient-derived tumor spheroids overexpressing NRP1 and an animal model comprising the same, and more particularly to a method of screening an antibody or an antigen-binding fragment thereof through in vitro and in vivo panning by use of a patient-derived tumor spheroid containing NRP1 and an animal model transplanted with the same, respectively.