The invention discloses a corrosion evaluation test dissolved oxygen content control device and method. The corrosion evaluation test dissolved oxygen content control device comprises a solution container, which stores a test solution to be purified; a dissolved oxygen monitoring unit, which is used for monitoring the content of dissolved oxygen in the test solution in the solution container; and a fluid flow control unit, which is used for controlling flow of the fluid in the device. The fluid flow control unit controls on/off and flow of purifying gas from a purifying gas unit to purify the test solution in the solution container; and the fluid flow control unit further controls the processed test solution in the solution container to be transferred to a solution storage unit. According to the device and method, through the function of the fluid flow control unit, medium circulation, purifying and solution transfer in connecting conduits are controlled to ensure the test solution reaches regulated dissolved oxygen content without causing secondary pollution.