With the high-hanging cableway without drawing deflection at Wulong Hydrometric Station on Wujiang River, the reliability of the bed load observation by AYT Sampler was analyzed in the stability of sampler on the surface of the river bed, stability of sampler in and out the water, bed scratching, and deflection from section. Based on the examination, the section transport rate was tested. The results show that the dependability of the AYT Sampler is better under the low and medium water level, but it is not convinced under the high flood water level. The conclusion is significant for guiding the bed load observation in the mountain river channels.