The utility model discloses a combined-type balance arm main pin and a suspension system. The balance arm main pin disclosed by the utility model comprises a main body; a fixed end cover is arranged at one end of the main body; the balance arm main pin is characterized by further comprising a detachable end cover and a fastening part; the detachable end cover is detachably connected with the other end of the main body; and the main body is connected with the detachable end cover via the fastening part. The balance arm main pin disclosed by the utility model is a combined structure with the two end covers; the main body and the detachable end cover are fixed by the fastening part, so that the balance arm main pin is easy to assemble and disassemble; and the assembling stability is improved.