The invention discloses a simple fecal sewage treatment device and a simple fecal sewage treatment method using the device. The simple fecal sewage treatment device comprises a pond, wherein a fecal storage tank is arranged at the bottom of the pond; a gas collecting cover covers the fecal storage tank; a stand column is arranged in the middle of the fecal storage tank; a gas outlet pipe extendingout of the gas collecting cover is arranged on the stand column; a vent hole is formed in a position, below the gas collecting cover, of the gas outlet pipe; the upper portion of the gas outlet pipeis positioned above the water surface and is provide with a liquid sealing pipe; and a feeding pipe and a discharging pipe are respectively arranged on the side wall of the fecal storage tank. According to the device and the method, biogas production device is built below the pond, therefore, not only can the fecal from a breeding farm be treated through anaerobic and aerobic combination, but alsothe biogas can be directly conveyed to peripheral users for use by utilizing the pressure of water, that is, the produced biogas does not need to be additionally pressurized; and meanwhile, fish canbe cultured above the pond, and multiple benefits are produced.