A self-suction type side door lock assembly is formed by combined mounting of a mechanical assembly and a central control assembly. The mechanical assembly comprises a cover plate subassembly, a lock body subassembly and a circuit board subassembly. The cover plate subassembly comprises a ratchet wheel-pawl mechanism and a self-suction rocking arm mechanism. The lock body subassembly comprises a ratchet wheel return spring, a ratchet wheel signal rocking arm, a self-suction guide plate, a guide plate return spring, a guide plate shaft, a pawl return spring, a latch damping pad and a locking connection rod, wherein the ratchet wheel return spring and the ratchet wheel signal rocking arm are arranged on a lock body. An external-unlocking rocking arm and an external-unlocking universal driving shaft which are riveted together are arranged on a pawl shaft through an external-unlocking return spring and an external-unlocking riveting gasket. The central control assembly comprises an inner cavity formed by a shell and a shell cover, and a signal circuit board, a push rod, a locking linkage arm, an external-locking linkage arm, an internal-locking linkage arm, a lock cylinder rocking arm shaft and a lock cylinder rocking arm are arranged in the inner cavity. The self-suction type side door lock assembly is simple and skillful in structure and powerful in function, and transmission efficiency and transmission stability are improved greatly.