The invention discloses a high-rigidity tubular micro-filtration membrane and a preparation method thereof. The preparation method comprises the steps that 1) HDPE, an antioxidant and a nano-reinforcing agent are put into a mold, and sintering is carried out for 4-8 hours at the temperature of 120-200 DEG C so as to obtain a supporting framework, wherein the supporting framework is prepared from the materials, by mass percent, 85-95% of the HDPE, 0.5-2% of the antioxidant and 4.5-13% of the nano-reinforcing agent; 2) a membrane casting solution is kept standing for defoaming; and 3) microporesof the supporting framework is filled with the membrane casting solution, and the phase-separation membrane forming process is carried out to form the membrane of an anchor structure in the inner surface and the micropores of the supporting framework so as to obtain the high-rigidity tubular micro-filtration membrane. According to the high-rigidity tubular micro-filtration membrane and the preparation method thereof, HDPE particles are adopted to prepare the supporting framework of the tubular micro-filtration membrane, and therefore the wear resistance and the corrosion resistance of the tubular micro-filtration membrane is remarkably improved, the structural stability is good, and the service life of the tubular micro-filtration membrane is prolonged.