The disclosure discloses a loopback structure and data loopback processing method of a processor. The loopback structure includes a register file unit, a data storing unit, and a data reading unit; wherein the register file unit is configured to provide a data reading-writing service for the data storing unit and the data reading unit; the data storing unit is connected to the register file unit, and is configured to read data via a reading port of the register file unit, to perform a data transformation on the read data, and to feed the transformed data back to the data reading unit; and the data reading unit is connected to the register file unit and the data storing unit, and is configured to transform the data fed back by the data storing unit, and to write the transformed data in the register file unit via a writing port of the register file unit. With the disclosure, it is possible to increase efficiency of the processor and decrease power consumption of the processor.