To understand the eco-hydraulics characteristics of Biomphalaria straminea, the intermediate host of Schistosoma mansoni.The drainage method and settlement tube method were applied to measure B. straminea's density and hydrostatic settling velocity respectively.The density of B. straminea was 1.04-1.16 g/cm3, and the average value was 1.08 g/cm3. The hydrostatic settling velocity was 2.32-12.92 cm/s.The eco-hydraulics characteristics of B. straminea is different from Oncomelania hupensis, and more attention should be paid to the hydraulic measures for the control of B. straminea.