To quantitatively analyze the evolution process of the transportation and accumulation of aggregates in the water inrush channel, aggregate perfusion experiments under dynamic water conditions were carried out, and the inherent correlations between the initial deposition position, the formation direction, the maximum accumulation height, and influencing factors such as water flow rate and aggregate filling speed were obtained. The result shows that under a high flow rate dynamic water environment of 1.0 m/s, the initial formation direction of aggregate is first against the movement of water flow and then turned to the tip of water flow after growing to the bottom of the filling hole. Under the same injection amount, compared with using an 18 mm funnel, the maximum height of the accumulation can be increased by up to 41% by using a 36 mm filling funnel. Based on the two-phase flow coupling calculation model by CFD-DEM (computational fluid dynamics and distinct element method), the spatiotemporal distribution characteristics of the flow field during aggregate perfusion and the influence mechanism of the overwater resistance of the accumulation on the static water pressure in the water inrush channel were studied.