In view of lack of continuous knot-tying performance test and fatigue test system of knotter in China, a kind of continuous knot-tying test method of knotter and design scheme of knotter fatigue test bench were proposed to simulate straw-bundling processes of square baler. By designing a rope-pulling device which can simulate springback characteristic of straw bale, the device moved on horizontal plane to pull rope according to rectangle path, and a rectangle rope ring was formed on vertical plane in cooperation with rope-sending motion of rope needle, and the tested knotter finished knot-tying. The test bench realized rope-pulling, rope-sending and knot-tying motion circularly, and tension force of the rope, torque and rotation angle of the main shaft can be measured at the same time. 3D model of mechanical system of the test bench was established under the software of Solidworks according to the proposed scheme, and type selection of its key parts was done. Parameters measurement and motion control system of the test bench was built up, and control flow of the test bench was designed on the basis of the logic among rope-pulling, rope-sending and knot-tying motion. Graphical programming language of LabVIEW was used to program the measurement and control program of the test bench. The running test results of knotter fatigue test bench showed that the mechanical system, measurement and control system of the test bench worked reliably, and continuous knot-tying efficiency of the test bench reached three knots per minute. The test bench may provide a test platform for knotter development and short-term fatigue life evaluation of knotter.