The invention discloses a synchronous measurement device of short-circuit current distribution in a transformer substation. The synchronous measurement device of the short-circuit current distribution in the transformer substation comprises a plurality of oscilloscopes, wherein an external trigger signal of an oscilloscope serves as trigger source of other oscilloscopes, the other oscilloscopes and the oscilloscope are in parallel connections respectively through coaxial cables to achieve synchronous trigger of all oscilloscopes; the oscilloscope is connected with a current transformer, total fault current can be measured by the current transformer when a short-circuit ground fault occurs; the other oscilloscopes all correspond to and connect with the current transformers, and ground current and transformer neutral point current can be measured by the corresponding current transformers when the short-circuit ground fault occurs. The device is used for synchronously measuring the short-circuit current distribution in the transformer substation when the short-circuit ground fault occurs. The invention simultaneously discloses a synchronous measurement method of the short-circuit current distribution in the transformer substation.