Due to the limitation of shallow water depth and other factors in the construction area,the final top level of throwing area is prohibited to exceed the required level.Otherwise,the soil exceeded the agreed elevation should be carried out secondary treatment,and it requires higher construction precision to underwater throwing and filling of mud barge.Based on the dredging project in southern channel of Ukraine,we adopt mathematical model to analyze the movement of different particles under different construction conditions,and improve the positioning,throwing and filling and subsequent treatment method of the soil.The results show that the improved construction technology can effectively control the quality of throwing and filling in the construction area.