The invention discloses a method for quickly determining the outage of a distribution transformer, and the method comprises the following steps: (1), obtaining the corresponding monitoring data and basic data, building a station-main line-branch line-distribution transformer-user side topological relation, and finally determining whether the station power failure is caused by a high-voltage side power failure or not through monitoring whether other stations of the same branch line have power failures or not and the power failure conditions of the stations of different branch lines of the same main line; (2), carrying out the real-time measurement of the data of a key user intelligent meter of the main station after the power failure of the distribution transformer happens, and determining whether the power failure of the station is caused by a power failure of a low-voltage line or not; (3), carrying out the real-time measurement of a key electrical quantity of a station collector through the main station after the power failure of the distribution transformer happens, and determining whether the power failure of the station is caused by a fault of a collection terminal or not. The method can quickly determine a power-failure segment of the distribution transformer, enables the power-failure segment of the distribution transformer to be divided into a main line power failure segment, a branch line power failure segment, a station power failure segment and a collection terminal fault segment, and greatly reduces the searching time of the power failure of the distribution transformer.