A hydraulic-oil control device that controls a supply of hydraulic oil to a first hydraulic chamber for disengaging and engaging a first clutch in a dual clutch device including the first clutch and a second clutch and enabling to switch a driving force transmission path from a driving source to a transmission to be switched between two systems, controls a supply of hydraulic oil to a second hydraulic chamber for disengaging and engaging the second clutch, and controls a supply of hydraulic oil to a first space that surrounds a first clutch plate of the first clutch and a second space that surrounds a second clutch plate of the second clutch, comprising: a first linear solenoid valve configured to adjust hydraulic oil having a predetermined line pressure to supply the adjusted hydraulic oil to the first hydraulic chamber; a second linear solenoid valve configured to adjust hydraulic oil having the line pressure to supply the adjusted hydraulic oil to the second hydraulic chamber; a shuttle valve configured to output hydraulic oil having a higher pressure between a pressure of hydraulic oil in the first hydraulic chamber and a pressure of hydraulic oil in the second hydraulic chamber; and a hydraulic oil amount adjusting valve configured to adjust an amount of hydraulic oil supplied to the first space and the second space according to a pressure of hydraulic oil output from the shuttle valve; characterised in that the hydraulic oil amount adjusting valve is connected to a minimum amount pipe having a channel cross-sectional area that enables to supply a minimum amount required for lubrication in the first and second space, a maximum amount pipe having a channel cross-sectional area that enables to supply a maximum amount used for lubrication in the first and second space, and a lubricating pipe that communicates with the first space and the second space, and the hydraulic oil amount adjusting valve switches a state in which the lubricating pipe and the minimum amount pipe are communicated with each other and a state in which the lubricating pipe and the maximum amount pipe are communicated with each other according to a pressure of the hydraulic oil output from the shuttle valve. a first linear solenoid valve configured to adjust hydraulic oil having a predetermined line pressure to supply the adjusted hydraulic oil to the first hydraulic chamber; a second linear solenoid valve configured to adjust hydraulic oil having the line pressure to supply the adjusted hydraulic oil to the second hydraulic chamber; a shuttle valve configured to output hydraulic oil having a higher pressure between a pressure of hydraulic oil in the first hydraulic chamber and a pressure of hydraulic oil in the second hydraulic chamber; and a hydraulic oil amount adjusting valve configured to adjust an amount of hydraulic oil supplied to the first space and the second space according to a pressure of hydraulic oil output from the shuttle valve; characterised in that the hydraulic oil amount adjusting valve is connected to a minimum amount pipe having a channel cross-sectional area that enables to supply a minimum amount required for lubrication in the first and second space, a maximum amount pipe having a channel cross-sectional area that enables to supply a maximum amount used for lubrication in the first and second space, and a lubricating pipe that communicates with the first space and the second space, and the hydraulic oil amount adjusting valve switches a state in which the lubricating pipe and the minimum amount pipe are communicated with each other and a state in which the lubricating pipe and the maximum amount pipe are communicated with each other according to a pressure of the hydraulic oil output from the shuttle valve.