The present invention relates to a device for crushing a hydrous polymer jelly, comprising two rolls (11,12) located axially parallel and rotating in opposite directions between which a nip (13) for the passage of the polymer gel (10) is formed. In order to achieve a more uniform and cheaper size reduction of polymer gels, the present invention proposes to form one roll as a cutting roll (11) which is provided with at least one axially extending cross cutting element (15) having a cutting edge (17) and with a radially extending longitudinal cutting element (14) provided with a cutting edge (18) which runs around it, and to form the other roll as a back-up roll (12).