The invention discloses an auxiliary filling magazine well used for AK series rifles. The auxiliary filling magazine well is characterized by comprising a magazine well body, a pressing plate, a magazine buckle fixing part and a screw; the magazine well body is composed of two side guide plates in bilateral symmetry and a front guide plate connected with the top ends of the front portions of the left and right side guide plates; the inner outline of the lower end face of the magazine well body is larger than the outer outline of the cross section of the top of the magazine, the upper edge of the rear end face of the front guide plate is connected with a lower hook of a gun tube base, the inner surface of the rear end of the magazine well body is provided with matching faces matched with the two sides of a handguard, and the magazine well body and the fixed pressing plate hold the handguard to be fixed together. The auxiliary filling magazine well is simple in whole structure, proper insize, and convenient to dismount and mount, an auxiliary device used for guiding the magazine to be smoothly filled into a gun receiver can be rapidly provided for the AK series rifles, gun operatorscan more rapidly finish the action of filling the magazine under the condition that a gun operator is in poor sight or in the emergency condition, and the man-machine effect of the rifles can be obviously improved.