The invention relates to a bar section bundling robot capable of achieving uniform stress during bundling of steel bundles. According to the robot, an upper arm and a lower arm are arranged on a machine frame, a first cylinder is arranged on the upper arm and can move left and right relative to the upper arm, and a first piston and a first connecting rod in the first cylinder can move vertically; a telescopic nail box is arranged at the bottom end of the first connecting rod, and a table board used for accommodating steel bundles is arranged on the lower arm in a left-right sliding fit mode; a second cylinder is fixedly arranged on the bottom of the lower arm, a second piston and a second connecting rod on the top of the second piston are arranged in the second cylinder, a pair of grooves are formed in the top surface of the second connecting rod, and when the first connecting rod and the second connecting rod are aligned and pressed, nails can penetrate through the grooves and tighten a rubber belt used for bundling the steel bundles; a pressing block which can move relative to the second connecting rod and is used for clamping the end of the rubber belt is arranged on the right side of the second connecting rod. By the adoption of the robot, loose bundling is avoided during bundling, bundle loosening caused by steel displacement does not occur easily after bundling.