The invention relates to a low-temperature continuous heat treatment fixed-bed reactor and a method thereof. The reactor of the present invention has a feed inlet, a shell, a reaction chamber, and a feed outlet. The feed inlet is located above the feed outlet. The feed end and the discharge end, the feed screw is below the feed port and the upper part of the feed end, the discharge screw is above the discharge end, and the discharge end is above the discharge port; the feed screw includes the center screw and the left, The right helical blade, the central screw crosses the left and right helical blades, the left and right helical blades are perpendicular to the center line of the central screw to form axisymmetric, and the spacing is 1/3 to 1/2 of the diameter of the feed port. The invention can realize continuous material feeding and discharging under the condition of hot state, has low equipment failure rate and high economic benefit.