The invention discloses a rope supporting device of an endless-rope winch. The rope supporting device is capable of prolonging service lives of rope supporting wheels, reducing transport cost and reliving workload and comprises rails, a sleeper, a rope support and two rope supporting wheels. The rails are fixed to two ends of the sleeper respectively, the rope supporting wheels are rotatably connected to the rope support which is provided with a left supporting plate and a right supporting plate, the sleeper is provided with grooves corresponding to bottoms of the left and right supporting plates, the bottoms of the left and right supporting plates are embedded into the grooves, and the sleeper on the right side of the left and right supporting plates is provided with four grooves at equal intervals. The two rope supporting wheels are arranged on the rope support longitudinally, outer sides of the bottoms of the left and right supporting plates are provided with lugs protruding outwards, and the lugs are fixedly connected with the sleeper through bolts. The rope supporting device has advantages that maintenance workload relief and transport cost reduction are realized while endless-rope transport requirements are met.