An aliquoting device comprises a horizontal conveyer belt (11), a first stopping assembly (12), a second stopping assembly (15), a material tank (20), a aliquoting head (21), a first sensing piece (31), a second sensing piece (32) and a control unit (33). The horizontal conveyer belt is used for conveying containers and is provided with an entering station, a filling station and a conveying direction. The first stopping assembly is arranged on the entering station and comprises a first baffle (13) and a first lifting drive piece (14). The second stopping assembly is arranged on the filling station and comprises a second baffle (16) and a second lifting drive piece (17). The aliquoting head communicates with the material tank. The first sensing piece is arranged on the entering station. The second sensing piece is arranged on the filling station. The control unit is in signal connection with the first sensing piece, the second sensing piece, the first lifting drive piece, the second lifting drive piece and the aliquoting head. The aliquoting device can automatically and accurately aliquot matter to be aliquoted into multiple containers.