Abstract: The present disclosure relates to a feedforward structure for controlling water level, in particular to a feedforward structure for controlling a steam drum water level in a steam turbine FCB test and a control method therefor. The feedforward structure includes a steam drum provided with a steam drum water level measurement sensor therein, a feed water pipe provided with a feed water flow measurement sensor therein, and a steam inlet pipe provided with a steam flow measurement sensor therein. A steam drum water level measurement value I in the steam drum water level measurement sensor is compared with a set value of the steam drum water level.