The invention provides an underwear fabric and a processing technique thereof. The underwear fabric is made by circularly weaving upper unilateral weaves, needle-containing double-sided weaves and lower unilateral weaves, and air layers are arranged between the upper unilateral weaves and the needle-containing double-sided weaves and between the needle-containing double-sided weaves and the lowerunilateral weaves. The underwear fabric is smooth in hand feeling, close-fitting, capable of keeping warm, dry and cool, comfortable, breathable and good in shape keeping capability, and has the advantages of high density, good drooping performance and good color fastness. The processing technique is simple, the energy is saved, the consumption is reduced, the prepared fabric is used for processing of integrated seamless underwear, the molding of mold cloth is more stereoscopic and comfortable, the situation that traditional underwear sponge mold cloth is thick and easy to deform is avoided, the excellent washability and fastness can be provided, and a new wearing experience is brought.