The invention discloses a method for treating sewage of a hybrid membrane bioreactor, which relates to a method for treating the sewage of a membrane bioreactor. The method solves the problems that the prior sewage treatment method has low treatment efficiency and large output of excess sludge. The treatment method is realized by the following steps that: 1. activated sludge and particle fillers are added in the membrane bioreactor for bio-film colonization, and the bioreactor is started; 2. the sewage is subject to the hydrolytic acidification treatment in an anoxic zone; 3. the sewage treated by the step 2 passes through a thin grille arranged between the anoxic zone and an aerobic zone, enters the aerobic zone, and performs nitrification treatment in the aerobic zone; 4. and the sewage is filtered by a membrane module in the hybrid membrane bioreactor and then is drained. In the method, removal rate of COD can reach between 85 and 95 percent, and the output of the excess sludge can be reduced by between 50 and 85 percent compared with an activated sludge treatment method; compared with the prior membrane reactor treatment method, the output of the excess sludge can also be reduced by between 20 and 50 percent.