The invention discloses a method for accelerating the start process of a rapidly started anaerobic ammonia oxidation reactor. The method comprises the following steps: inoculating nitrification sludge into an ABR reactor, an SBR reactor and an MBR reactor so as to obtain the result that the MBR reactor is beneficial to start of anaerobic ammonia oxidation; inoculating different sludge sources in the MBR reactor, and screening sludge sources which are most beneficial to rapid start of anaerobic ammonia oxidation; finally optimizing process operation conditions and process operation parameters of anaerobic ammonia oxidation, and accelerating the anaerobic ammonia oxidation start process. A great number of tests are carried out for MBR, a great deal of experience and achievement are obtained, MBR and anaerobic ammonia oxidation are combined together for the characteristics that the anaerobic ammonia oxidation start time is long and the sludge increase rate is low, optimal sludge sources are selected for inoculation, the process operation conditions and the process operation parameters for rapid start of anaerobic ammonia oxidation are tested, and thus the novel high-efficiency denitrification technique can be applied to practical production in a large scale as soon as possible.