The invention discloses an analog loading test device of a walking chassis speed changing box of a combine harvester, comprising an installation base, a drive part, a speed changing box fixing device, a loading part, a vibration measuring system, a noise measuring system, a box body temperature measuring system, a lubricating oil temperature measuring system and a central control cabinet. According to the invention, a speed governing motor is used as power, two magnetic powder brakes independently apply working loads, the whole system is provided with three sets of torsion rotating speed sensors, one set of vibration detection system, one set of noise detection system and one set of box body temperature and oil temperature system, and all detection signals are transmitted to an industrial control machine of the central control cabinet and displayed in real time and recorded and stored; control signals of the magnetic powder brakes are provided by an analog output card and are programmed in control software; and two paths of output voltages are respectively controlled by using a function, thus simulation of a complex working condition can be realized, and a fatigue test can be carried out.