A hydraulic controlling system, wherein the hydraulic controlling system comprises: a cooling and lubricating oil line and a main controlling oil line; an oil-liquid storage; a first pump, wherein an inlet of the first pump is connected to the oil-liquid storage, and an outlet of the first pump is connected to the main controlling oil line; a second pump, wherein an inlet of the second pump is connected to the oil-liquid storage, and an outlet of the second pump selectively communicates with the cooling and lubricating oil line or the main controlling oil line; and a gearbox-gear-shifting oil line, wherein the gearbox-gear-shifting oil line comprises a gear-shifting-pressure regulating valve, a plurality of gear-shifting-flow-rate controlling valves and a plurality of gear-shifting selector valves, the gear-shifting-flow-rate controlling valves are connected to the main controlling oil line via the gear-shifting-pressure regulating valve, and at least some of the plurality of gear-shifting-flow-rate controlling valves are connected to a gear-shifting executing piston via the gear-shifting selector valves; the hydraulic controlling system is characterised in that the hydraulic controlling system is configured to, in a gear-shifting starting stage, maintain an outputted pressure of the gear-shifting-pressure regulating valve at a first preset pressure, and regulate gear-shifting flow rates by using the gear-shifting-flow-rate controlling valves, and the hydraulic controlling system is configured to, in a gear-shifting synchronizing stage, maintain a controlling source of the gear-shifting-flow-rate controlling valves unchanged, and increase the outputted pressure of the gear-shifting-pressure regulating valve. a cooling and lubricating oil line and a main controlling oil line; an oil-liquid storage; a first pump, wherein an inlet of the first pump is connected to the oil-liquid storage, and an outlet of the first pump is connected to the main controlling oil line; a second pump, wherein an inlet of the second pump is connected to the oil-liquid storage, and an outlet of the second pump selectively communicates with the cooling and lubricating oil line or the main controlling oil line; and a gearbox-gear-shifting oil line, wherein the gearbox-gear-shifting oil line comprises a gear-shifting-pressure regulating valve, a plurality of gear-shifting-flow-rate controlling valves and a plurality of gear-shifting selector valves, the gear-shifting-flow-rate controlling valves are connected to the main controlling oil line via the gear-shifting-pressure regulating valve, and at least some of the plurality of gear-shifting-flow-rate controlling valves are connected to a gear-shifting executing piston via the gear-shifting selector valves; the hydraulic controlling system is characterised in that the hydraulic controlling system is configured to, in a gear-shifting starting stage, maintain an outputted pressure of the gear-shifting-pressure regulating valve at a first preset pressure, and regulate gear-shifting flow rates by using the gear-shifting-flow-rate controlling valves, and the hydraulic controlling system is configured to, in a gear-shifting synchronizing stage, maintain a controlling source of the gear-shifting-flow-rate controlling valves unchanged, and increase the outputted pressure of the gear-shifting-pressure regulating valve.