Abstract: This study proposes a novel and efficient prefabricated RC beam-column joint, where the connection between the prefabricated beam and the lower prefabricated column is achieved by casting concrete in the joint core area. The connection between the upper and lower prefabricated columns is set above the joint core area, and is realized by welding steel sleeves pre-embedded at the ends of the prefabricated columns. The experiment designed one prefabricated joint specimen and one cast-in-place joint specimen, and studied their seismic performance through quasi-static tests. The results show that the prefabricated joint exhibits bending failure at the beam end, with the column end remaining intact and only two cracks appearing in the joint core area, conforming to the “strong column-weak beam” design principle. During the loading process, the prefabricated joint goes through three stages: linear, elastic, and failure, with the hysteresis curve being the fullest in the elastic stage, indicating good energy dissipation performance. Compared with the cast-in-place specimen, the prefabricated joint shows a consistent trend of stiffness degradation, with a 7% lower negative peak bearing capacity and a 0.34 lower ductility coefficient.