Based on the design requirements of the side channel spillway of the water allocation pool in Huangchigou Water Distribution Hub, the hydraulic characteristics of the side channel spillway was investigated through hydraulic model tests. The hydraulic parameters including flow velocity, pressure and water depth were measured, based on which the conveyance capacity of the side weir, water surface profile, cavitation of the steep slope flow and flow pattern of the stilling basin were analyzed. The results show that the conveyance capacity of the side weir under the designed discharge meets the requirements, as well as the height of the side wall. The phenomenon of alternating pressure and non pressure flow will not occur in the Qinling tunnel. The steep slope is unlikely to be damaged by cavitation. The flow in the stilling basin doesn’t meet the requirements for the dissipation of hydraulic jumps when the flow rate increases. It is recommended that further model tests should be carried out to redesign the stilling basin.