The coaxial annular channels’ experimental platform is built to study its flow characteristics when S/d0=2.0, S/d0=2.5, S/d0=3.0, and it is compared with circular pipe’s theoretical value. The purpose is to study the influence of flow rate, pressure, flux, heat transfer temperature and geometric parameters on the coaxial annular channels’ flow characteristics of spiral tube heat exchanger. The results show that for the same annulus width and outside diameter of spiral tube, annular channels’ import, export and total resistance coefficients are decreasing and tend to constants gradually as Reynolds number increases; all the resistance coefficients of annular channel’s outer ring are bigger than those of annular channel’s middle ring and inner ring. But the resistance coefficients of annular channel’s middle ring and inner ring are equal; under the same Reynolds number, the smaller the annulus width is, the bigger pressure drop of annular channel is.