The invention discloses a prefabricated assembly type beam column joint connecting process. The process comprises the steps that a frame column comprising three rows of threaded sleeves is prefabricated; a pore passage is reserved in the lower end of each prefabricated frame beam, a connecting steel bar on the lower portion of each frame beam is inserted in the corresponding reserved pore passage, and a gap is kept between each frame beam and the frame column; a connecting steel bar on the upper portion of each frame beam is connected with the upper threaded sleeves, the connecting steel bar on the lower portion of each frame beam is connected with the lower threaded sleeves, and detachable supporting pieces are connected with the reinforced threaded sleeves; the reserved pore passages are filled with high-strength mortar; a prefabricated plate is hoisted and placed on each frame beam, and beam and plate laminating layers are formed in a pouring mode through concrete to complete wet joint connection. By means of the process, the frame beams on the two sides of the frame column can be connected together, the overall structural stability can be improved, no weld spot exists, high-altitude welding operation is avoided, the safety risk is lowered, and connection between the frame column and the frame beams is more stable and reliable by means of pouring of the wet joint concrete and the high-strength mortar; moreover, construction is fast, and the construction efficiency is improved.