The invention relates to a characteristic measurement system and method for a network distribution bus PT signal, and a transformer substation, and belongs to the technical field of the electric system automation. The system comprises a programmable logic device capable of performing synchronous control on multiple analog-to-digital converters, a SRAM cache module, multiple network distribution network bus PT signal devices, and a trigger module; each network distribution bus PT signal performs data interaction with an I/O port of the programmable logic device after passing through a signal conditioning module and the ADCs in order; a communication port is arranged on the I/O port of the programmable logic device; and the trigger module performs data interaction with the I/O port of the programmable logic device. The synchronous collection is triggered by unifying the external synchronous trigger signals, thereby realizing the high-precision synchronous collection between multiple channel bus PT signals. The collection standard is obviously improved, and the 20 thousand-point voltage waveform sampling can be reached at each cycle of the power distribution network. And a data precision requirement for the network distribution bus running state measurement at the new period is satisfied.