A paint circulation system includes: a main line; a branch line; a supply pump; and a pressurization device for storing pressure of the paint in a high-pressure state in which the pressure of the paint is higher than a predetermined pressure, and for applying pressure to the paint inside of the branch line in a low-pressure state in which the pressure of the paint is lower than the predetermined pressure, in which sedimentation of the paint is prevented by driving the supply pump so that the high-pressure state and the low-pressure state occur, to cause flow sending the paint inside of the branch line from a side of the painting device to a side of the main line using a pressure difference between the predetermined pressure in the low-pressure state and the pressure of the paint.