The invention provides a method for treating urban domestic sewage through multistage microfiltration. In the method, a first-stage microfiltration screen, a second-stage microfiltration screen, a third-stage microfiltration screen, a fourth-stage microfiltration screen, a fifth-stage microfiltration screen, a sixth-stage microfiltration screen, a seventh-stage microfiltration screen, an eighth-stage microfiltration screen, a ninth-stage microfiltration screen and a tenth-stage microfiltration screen as well as a first-stage residue-filtering screen, a second-stage residue-filtering screen, a third-stage residue-filtering screen, a fourth-stage residue-filtering screen, a fifth-stage residue-filtering screen, a sixth-stage residue-filtering screen, a seventh-stage residue-filtering screen, an eighth-stage residue-filtering screen, a ninth-stage residue-filtering screen and a tenth-stage residue-filtering screen are used; the domestic sewage is threated through first-stage microfiltration and first-stage residue filtration, second-stage microfiltration and second-stage residue filtration, third-stage microfiltration and third-stage residue filtration, fourth-stage microfiltration and fourth-stage residue filtration, fifth-stage microfiltration and fifth-stage residue filtration, sixth-stage microfiltration and sixth-stage residue filtration, seventh-stage microfiltration and seventh-stage residue filtration, eighth-stage microfiltration and eighth-stage residue filtration, ninth-stage microfiltration and ninth-stage residue filtration, and tenth-stage microfiltration and tenth-stage residue filtration; the treated water reaches a certain standard; the first-stage microfiltration, the second-stage microfiltration, the third-stage microfiltration, the fourth-stage microfiltration, the fifth-stage microfiltration, the sixth-stage microfiltration, the seventh-stage microfiltration, the eighth-stage microfiltration, the ninth-stage microfiltration and the tenth-stage microfiltration adopt different microfiltration screens and different types of microfiltration media, and a good condition is created for improving the sewage treatment efficiency of a next-stage microfiltration machine. By the method, on one hand, the treated water is classified, so that the sewage treatment cost is correspondingly reduced and the utilization rate of water resources is correspondingly increased; on the other hand, the filtered sludge is also classified by a continuous multistage microfiltration technology, a good condition is created for effective sludge utilization.