The utility model discloses a making devices of soft clay of seabed gassiness. The device includes cylindrical housing, is located cylindrical housing's first permeable stone, the second permeable stone, go up the roof, cylindrical housing by the heat insulation layer with lie in adiabatic intraformational heat -conducting layer and form, the device is at first through placing the heavy object in last roof top to through two weeping rock drainages, concrete it, then heat it with the heat -conducting layer through setting up in the very steady heater of bottom, thereby make the bubble that produces evenly distributed in the soil sample, the actual sea bed gassiness of simulation system appearance is native. The utility model discloses has the advantage that the soil sample gassiness is even, the native preparation of gassiness can repeat, the preparation time short and the installation cost is economized simultaneously, the utility model discloses a but research is difficult for the normal position and obtains extensively to distribute and provide the basis of artifical simulation in the mechanics characteristic of the soft clay of gassiness in three big sea areas in the china.