The invention provides a preparation method of a silicon carbide asymmetric composite filter tube membrane with controllable aperture, and a device, and belongs to the technical field of gas-solid separation. The method comprises the following steps: firstly, crushing and grinding raw materials, then carrying out mixing, carrying out pelletizing and mixing, carrying out isostatic pressing, carrying out drying, then carrying out firing, and carrying out plasma spraying, wherein the used raw materials are silicon carbide, kaolin, aluminum oxide, a pore-forming agent, a sintering aid and a binder. The device applying the prepared filter tube membrane comprises an air outlet, a pressure transmitter opening, an air bag slag discharging opening, a pulse nozzle, an air inlet, a sewage dischargingport, the silicon carbide asymmetric composite filter pipe membranes and a blowback opening. 20-960 silicon carbide filter tubes are installed in a filter chamber in the middle of the device; dust-containing flue gas enters the filter chamber from the air inlet; and clean gas filtered by the silicon carbide filter pipe enters an internal pipeline of the device from the pulse nozzle and is finallydischarged from the air outlet. The silicon carbide asymmetric composite filter tube membrane has the advantages of excellent high-temperature corrosion resistance and thermal shock resistance, goodfiltration performance, high filtration precision, long service life and the like.