The invention discloses a rotary feeding pulverized coal quantitative feeding and conveying device and a method. The feeding device consists of a locking hopper system, a pulverized coal looser, a pressing feeder, a pulverized coal flow meter and related control valves; the locking hopper system realizes feeding of pulverized coals from normal pressure to increased pressure; the lower part of a feeding hopper is connected with the pulverized coal looser for preventing bridge blockage of the pulverized coals; the lower part of the pulverized coal looser is connected with the pressing feeder; the continuous and stable feeding of the pulverized coals is realized through a mechanical rotary feeding mode; the lower part of the pressing feeder is connected with a pneumatic conveying device; and materials are continuously fed into reaction equipment through a pneumatic conveying mode. The feeding device realizes pressed, continuous and quantitative feeding of the pulverized coals through matching the locking hopper feeding system with the pressing feeding system and the pneumatic conveying system, guarantees the stability of the feeding system, and is convenient for operation, simple in control, accurate in metering and capable of being widely applied to feeding of the pulverized coals with different particle sizes and other solid materials.