A work machine, comprising: an engine, a hydraulic oil tank that holds hydraulic oil, a hydraulic pump that is driven by the engine and delivers the hydraulic oil in the hydraulic oil tank as pressure oil, a standard brake valve that is supplied with the pressure oil delivered by the hydraulic pump, a brake pedal that allows the standard brake valve to open or close, and a hydraulic brake that is operated with the pressure oil supplied from the standard brake valve, the work machine including: an autonomous brake control valve that is supplied with the pressure oil delivered by the hydraulic pump, a first supply flow path in which the pressure oil is supplied from the hydraulic pump to the autonomous brake control valve, a second supply flow path in which pressure oil is supplied from the hydraulic pump to the standard brake valve, a high-pressure selector valve that is placed on a flow path in which pressure oil is supplied from the standard brake valve to the hydraulic brake, a flow path that connects the autonomous brake control valve and the high-pressure selector valve, characterised by an autonomous traveling controller that performs control for causing the work machine to travel in autonomous manner, and an autonomous brake controller that performs open or close control on the autonomous brake control valve in response to a braking instruction from the autonomous traveling controller; wherein pressure oil at a higher pressure between the pressure oil supplied from the standard brake valve and the pressure oil supplied from the autonomous brake control valve is supplied from the high-pressure selector valve to the hydraulic brake. an engine, a hydraulic oil tank that holds hydraulic oil, a hydraulic pump that is driven by the engine and delivers the hydraulic oil in the hydraulic oil tank as pressure oil, a standard brake valve that is supplied with the pressure oil delivered by the hydraulic pump, a brake pedal that allows the standard brake valve to open or close, and a hydraulic brake that is operated with the pressure oil supplied from the standard brake valve, the work machine including: an autonomous brake control valve that is supplied with the pressure oil delivered by the hydraulic pump, a first supply flow path in which the pressure oil is supplied from the hydraulic pump to the autonomous brake control valve, a second supply flow path in which pressure oil is supplied from the hydraulic pump to the standard brake valve, a high-pressure selector valve that is placed on a flow path in which pressure oil is supplied from the standard brake valve to the hydraulic brake, a flow path that connects the autonomous brake control valve and the high-pressure selector valve, characterised by an autonomous traveling controller that performs control for causing the work machine to travel in autonomous manner, and an autonomous brake controller that performs open or close control on the autonomous brake control valve in response to a braking instruction from the autonomous traveling controller; an autonomous brake control valve that is supplied with the pressure oil delivered by the hydraulic pump, a first supply flow path in which the pressure oil is supplied from the hydraulic pump to the autonomous brake control valve, a second supply flow path in which pressure oil is supplied from the hydraulic pump to the standard brake valve, a high-pressure selector valve that is placed on a flow path in which pressure oil is supplied from the standard brake valve to the hydraulic brake, a flow path that connects the autonomous brake control valve and the high-pressure selector valve, characterised by an autonomous traveling controller that performs control for causing the work machine to travel in autonomous manner, and an autonomous brake controller that performs open or close control on the autonomous brake control valve in response to a braking instruction from the autonomous traveling controller; wherein pressure oil at a higher pressure between the pressure oil supplied from the standard brake valve and the pressure oil supplied from the autonomous brake control valve is supplied from the high-pressure selector valve to the hydraulic brake.