The invention discloses a solid-state oxygen control device. The device comprises a container, a flow rate adjusting unit and a replenishment mechanism, wherein a dissolution chamber for holding leadoxide pellets is arranged in the container, and an inlet and an outlet which are communicated with the dissolution chamber respectively are formed in two ends of the container; the flow rate adjustingunit is arranged on the container and used for controlling the flow rate of a coolant in the container; the replenishment mechanism is connected with the dissolution chamber to replenish the lead oxide pellets for the dissolution chamber. By means of the arrangement of the replenishment mechanism and a return pipe, the problem that current solid state oxygen control cannot realize online replenishment is solved, high-power oxygen supply of a reactor device and online replenishment of the lead oxide pellets are realized, the concentration of oxygen in the coolant can be accurately controlled,so that a layer of dense oxide film is formed on the surface of steel, lead-based alloy is prevented from further penetrating into the steel, an anticorrosion effect is realized, key technical difficulties of a lead-based fast reactor or an ADS system are overcome, and long-term safe operation of an experimental loop and the lead-based fast reactor is ensured.