The invention provides a special-purpose single-slit flow-guiding device for compact gas used for compact and siro spinning. The special-purpose single-slit flow-guiding device comprises a flow-guiding plate arranged on a special pipe of a compact and siro spinning system. The top of the special pipe is provided with compact grooves. A channel, allowing fiber fringing to pass through, is formed between the flow-guiding plate and the special pipe. An inlet and an outlet of the channel where fiber fringing can pass through are respectively located at the front end and the back end of the flow-guiding plate. A flow-guiding groove is formed in the middle of the flow-guiding plate. An air ingress channel is formed between the left end of the flow-guiding plate and the special pipe. Enclosed space is formed by the right end of the flow-guiding plate and the special pipe. Or, an air ingress channel is formed between the right end of the flow-guiding plate and the special pipe. Enclosed space is formed by the left end of the flow-guiding plate and the special pipe. The special-purpose single-slit flow-guiding device for compact gas used for compact and siro spinning has following beneficial effects: compact negative pressure can be reduced to the maximum; consistency of compact negative pressure and compact airflow of the two grooves can be also effectively controlled in order to ensure quality of yarns; and by decreasing compact negative pressure, energy consumption is reduced so that the requirement for energy conservation is satisfied.