The invention relates to the technical field of spinning equipment, in particular to a negative pressure-type automatic-recovery machine for combing noil. Negative pressure provided by a centrifugal fan makes the noil sucked away from a dust cage of a combing machine, and the noil enters a noil transport pipeline; a noil separating unit separates most of air from the noil, and under the action of air pressure and its own weight, the noil falls into a noil storage box from the noil separating unit; the noil is transported outside the noil storage box for use through a noil transport device 7. The machine has the advantages that 1, the negative pressure is used to suck the noil away, and the noil of multiple combing machines can be automatically collected at the same time to reduce manpower; 2, the shape of the noil can be controlled to make the adsorption capacity between the noil and the dust cage weak, and therefore the noil can be sucked easily into a noil collecting box; 3, the noil is prevented from fluttering into the air to deteriorate the workshop environment; 4, the noil is sucked away timely to prevent the noil from winding outside the dust cage; 5, noil fibers cannot be damaged; 6, a dust filter can be arranged on the noil transport pipeline and the noil separating unit to conduct dust filtration treatment on the sucked air to reduce dust in the air.