The utility model discloses a device in simulation fresh water mussel habitat, it has the pipe of pressure (1) front end to be connected with water inlet (2) including pressing pipe (1), has the pipe of pressure (1) rear end to be connected with gradual change open channel (3), gradual change open channel (3) back tip is equipped with tail water bank (4), and tail water bank (4) rear end is connected with delivery port (5), water inlet (2) upward are connected with booster pump (7) through pipe (6), and booster pump (7) still are connected with delivery port (5) through pipe (6). The utility model discloses a pipe and booster pump make the water flow in having pressure pipe and gradual change open channel, simulate the living environment of pipeline pressure flow, open channel unconfined flow and velocity of flow gradual change, through adjusting booster pump pressure and breakwater height, can change the water velocity of flow and velocity of flow gradual change degree. The utility model discloses not only can be convenient for carry out indoor research, reduce the degree of difficulty and the cost of research, still have the effectual advantage of simulation.