A vehicle-mounted movable household and medical waste treatment device with a tail gas treatment system arranged horizontally is characterized by comprising a vehicle, an induced draft fan, a horizontal adsorber, a horizontal deduster, a first connecting pipe, a horizontal dehydrator, a horizontal quenching desulfuration and deacidification device, a second connecting pipe, a horizontal secondary combustion chamber, a pyrolyzing furnace, a water pump, a third connecting pipe, a fourth connecting pipe, a fifth connecting pipe and a liquid storage tank, wherein the liquid storage tank is arranged on the vehicle; the horizontal adsorber arranged on the liquid storage tank is connected with the induced draft fan through the corresponding connecting pipe; the horizontal adsorber is connected with the horizontal deduster through the fifth connecting pipe; the horizontal deduster is connected with the horizontal dehydrator through the first connecting pipe; the horizontal dehydrator is connected with the horizontal quenching desulfuration and deacidification device through the fourth connecting pipe; the horizontal quenching desulfuration and deacidification device is connected with the liquid storage tank through the third connecting pipe and connected with the secondary combustion chamber through the second connecting pipe; the secondary combustion chamber is arranged on the upper portion of the pyrolyzing furnace; and one end of the water pump is put in the liquid storage tank, and the other end of the water pump is connected with the horizontal quenching desulfuration and deacidification device. The vehicle-mounted movable household and medical waste treatment device is novel in structure, the tail gas treatment system is arranged horizontally, the overall height is decreased, and operation and vehicle transportation are facilitated.