The utility model discloses a milk brewing machine and a milk powder rationing device thereof. The milk powder rationing device comprises a milk powder box (1), a milk powder scraper device (2), a rotary shaft (6), a milk powder blocking sheet (3) and a limiting column (4), wherein a milk powder outlet (11) is formed in the bottom of the milk powder box (1); the milk powder scraper device (2) is arranged in the milk powder box (1); the rotary shaft (6) is fixedly connected with the milk powder scraper device (2); a through hole for allowing the rotary shaft (6) to penetrate through is formed in the milk powder box (1); the milk powder blocking sheet (3) is in damping connection with the rotary shaft (6) and is used for opening or closing the milk powder outlet (11); the limiting column (4) is used for limiting the rotation of the milk powder blocking sheet (3). According to the milk powder rationing device provided by the utility model, the accurate rationing of milk powder is effectively guaranteed.