The present invention provides a digital gain controller and a digital gain control method. The controller comprises a pilot frequency buffer module, a gain calculation module, a frame data delay module and a gain control state machine. The gain control state machine is configured to allow the pilot frequency buffer module to store pilot frequency values with a preset quantity for a target pilot frequency section according to a parallel sequence in a pilot frequency storage state, allow the gain calculation module to transfer the pilot frequency values from the pilot frequency buffer module toperform iteration calculation by employing a gain calculation formula in a gain factor updating state to obtain the gain factor corresponding to each pilot frequency value and store the gain factors,and perform multiplication and calculation of the gain factors, the pilot frequency point data belonging to the target pilot frequency section and the user data of the data section corresponding to the target pilot frequency section and perform storage in the gain factor popping state so as to greatly improve the processing speed of the base band and extend the application range of a base band processing chip.