A forming machine for fabric slats provides a strip material to be formed with hot ironing and cold ironing according to temperature in a complete procedure of hot working, wherein an entire surface of the strip material is contacted and the strip material moves linearly. The forming machine stably forms a slat of a curved cross section and includes a hot ironing module and a cold ironing module which are assembled as a linear hot-working assembly. The fabric strip impregnated with an adhesive agent is fed in at an end of the hot-working assembly through a feed device. The strip material is first thermally fused and ironed with surface contact when passing through the hot-working assembly and then is executed with cold ironing and shaping, thereby stably forming the slat of the curved cross section, which is outputted from a take-up device at the other end of the hot-working assembly.