lA homogeneous and dense MnO2 membrane with separating performance of ultrafiltration (UF) and microfiltration (MF) was successfully prepared, taking a sintered porous polyethylene (PE) tube as the support of the dynamically formed membrane and potassium permanganate as membrane material. And through a series of experiments, the effects of the concentrations of potassium permanganate and sodium formate in the membrane-forming solution, pH of the membrane-forming solution and the pore size of the support on the formation and the separation performance of dynamic membranes were studied. As a result, the forming conditions of the dynamic MnO2 membrane were acquired as follows: pore size of PE tube, 5-20 mu m; pH of membrane-forming solution, 5-7; concentration of KMnO4 in membrane-forming solution, 0.050-0. 100 g/L; ratio of KMnO4 to HCOONa, 1:1.5 or so. The membranes were applied to treat the diatomite mineral processing wastewater and oil refinery wastewater with stable performance and over 98% of turbidity removal rate. In addition, 5wt% HCl solution can be used for cleaning the MnO2 membrane and regenerating a new membrane on the substrate PE tube.