The invention discloses an automobile seat mounting bracket assembly. The assembly comprises a seat bracket and a sliding rail bracket, wherein the seat bracket comprises a horizontal mounting part and a vertical mounting part which are rotationally connected with each other; the bottom of the horizontal mounting part is fixedly connected with a positioning frame; the vertical mounting part comprises a backrest bracket and a headrest bracket which are detachably connected with each other; the sliding rail bracket comprises an upper sliding rail bracket and a lower sliding rail bracket which are glidingly connected with each other; the positioning frame is fixedly connected with the upper sliding rail bracket; the bottom of the upper sliding rail bracket is fixedly connected with an upper sliding rail connecting frame; the upper sliding rail connecting frame penetrates through the lower sliding rail bracket; the upper sliding rail connecting frame is connected with a force measurement device. The assembly has the benefits that the structure is simple, the assembly is compact in installation and firm in connection, the seat bracket and the sliding bracket are skillfully integrated, and the safety and the comfort of an automobile seat are guaranteed.