Large TSHD rainbowing medium-coarse sand reclamation is different from traditional reclamation in ship machine equipment,critical velocity and pipeline arrangement.Aiming at medium-coarse sand property,special software is developed to calculate the critical velocity and the lowest practical velocity for different particle sizes;based on pump property and pipeline friction characteristics,the best efficiencies of the typical TSHD are calculated;quick connector methodology is researched with immediate-levelling and post-levelling within reclamation area,which can improve large TSHD rainbowing medium-coarse sand reclamation working efficiency.