A combination of an optical module and a transmitting and carrying structure includes an optical module, at least one carrying seat, and two rollers. The at least one carrying seat is combined with the optical module, for mounting the two rollers. The two rollers are located at the two opposite sides of the optical module. The two opposite sides of the optical module are perpendicular to the movement direction of the optical module. Thus, the at least one carrying seat and the two rollers are used to support and transmit the optical module, so that the optical module may be well balanced. In addition, the assembly height and the cost of fabrication are reduced.