The invention relates to a method for quickly switching a power station boiler drum water level regulating system into automation, which comprises the steps that (1) a zero water level scale is set; (2) drum water level compensation is calculated; (3) deviation calculation is carried out on a drum water level set value and a water level measurement value after drum pressure compensation calculation, and deviation output acts as input of a main PID regulation module; (4) a main steam flow acts as feed-forward input of the main PID regulation module after being corrected by a main steam temperature compensation function f3(x), and the main steam flow and a feedback calculation result overlaid together to act as output of the main PID regulation module; and (5) deviation calculation is carried out on the output of the main PID regulation module and the feed water flow, a result of the deviation calculation acts as input of an auxiliary regulation loop PI, and proportional-integral calculation is carried out by the auxiliary regulation loop PI. The method provided by the invention improves the reliability, the economy and the stability of unit operations, and reduces the operating intensity and the load increasing time.