Vehicle parking brake apparatus

A vehicle parking brake apparatus, related to the technical field of vehicle brake cylinders, comprising a cylinder body (10), a cylinder seat (20), a first piston assembly, a first relief spring (31), a parking mechanism (40) and a cylinder cover (50); the cylinder body (10) being disposed on the cylinder seat (20), the cylinder cover (50) covering one side of the cylinder body (10), the cylinder body (10) and the cylinder cover (50) forming a first accommodation space (11), the cylinder cover being provided with a first mounting hole (51); the parking mechanism (40) comprising a mounting seat (41) disposed on the cylinder cover (50), a locking element (42) and a boost assembly (43), the mounting seat (41) being provided with a second mounting hole (411) at a position corresponding to the first mounting hole (51), and the locking element (42) being disposed in the second mounting hole (411); the first piston assembly comprising a first piston (32) and a first piston rod (33) peripherally provided with a ring-shaped groove (331), the first piston rod (33) extending out of the parking mechanism (40), the first relief spring (31) being sleevedly disposed outside the first piston rod (33), one end being connected to the first piston (32) and another end being connected to the cylinder cover (50); a periphery of the first piston rod (33) being provided with a ring-shaped groove (331) which may be used to clamp the locking element (42), the boost assembly (43) being connected to the mounting seat (41) and capable of pushing the locking element (42) to separate from the ring-shaped groove (331) under action of gas pressure, the parking mechanism (40) being in a released state.