A maternal-fetal blood group incompatibility treatment device based on clearance of pathogenic antibodies for use in the medical field is characterized in that, erythropoietin is used as inducer, ''O'' type human or monkey bone marrow cell positive for Rh were cultured, to increase the number of directionally developing erythroid cells, human or monkey bone marrow cells were fused with mouse or human myeloma cells to form hybridized cells, different concentrations of erythropoietin were selected according to different fusion cells, to induce the directional differentiation of hybridized cells,Hybrid cell clones were screened by HAT, The hybridization strains of Rh positive cells which can be expanded indefinitely in vitro were screened by Rh antibody, after industrial amplification, it isused as an adsorbent to make an adsorber and then a blood separator to form an in vitro therapeutic device. By adsorbing the pathogenic Rh antibody in maternal and fetal blood group incompatible maternal plasma, a cheap and safe method for the treatment of maternal and fetal blood group incompatible hemolytic disease without removing the plasma and its beneficial ingredients is established.