The invention discloses a filling assisting device. A filling assisting unit of the filling assisting device comprises a top beam, a base and two hydraulic columns connected between the top beam and the base, and a guide column is arranged between the hydraulic columns and connected between the top beam and the base. A filling tube socket is arranged at the front end of the base, and the lateral portion of the top beam is provided with a hanger for hanging filling moulds. Compared with a conventional hydraulic support of a four-link structure which is complicated in structure and heavy in overall weight, the filling assisting device is simple in structure, light in weight and low in cost as structures such as shield beams, four links, movable side plates, telescopic beams and edge protection plates are omitted and a structure that the columns and the guide columns support the top beam jointly is adopted.