Abstract: A buffer device has a plurality of positioning seats, a base seat disposed on the positioning seats, and a main cylinder and a plurality of auxiliary cylinders disposed on the base seat. The base seat has a main oil channel, a plurality of oil inlet channels communicating with the main oil channel, and a plurality of oil return channels communicating with the main oil channel. The main oil channel communicates with the auxiliary cylinders. The oil inlet channels communicate with the main cylinder. Each oil inlet channel has a one-way valve. The oil return channels communicate with the main cylinder. A release valve blocks each oil return channel. A compression spring is disposed in the main cylinder. A piston rod extends from the main cylinder. Each auxiliary cylinder has a coiled spring and a piston.