The invention discloses spunlaced nonwovens and a machining method for composite fiber curtain filtration. According to the method, copet composite fiber, whitening polyester fiber and superfine polyester fiber in the weight proportion 1.5: 2.5:1 are subjected to the following steps to form the spunlaced nonwovens, 1, the copet composite fiber, the whitening polyester fiber and the superfine polyester fiber are mixed in the weight proportion 1.5: 2.5:1; 2, the mixed material is conveyed to an air pressure cotton box carding machine through a draught fan after being subjected to mixing opening; 3, the mixed fiber is subjected to carding to form a mesh, and the mesh is conveyed to a spunlace machine; 4, spunlace machining is conducted on the mixed fiber on a spunlace machine; 5, dehydration treatment is conducted; 6, the mixed fiber is transferred to a dryer to be subjected to continuous drying solidification after the spunlace machining, the solidification temperature of a first drying oven is 160+-3 DEG C, the solidification temperature of a second drying oven is 170+-3 DEG C, and the speed is 45-50 m / min; 7, calendering finish is conducted; 8, the working procedures of slitting and packaging are conducted. The spunlaced nonwovens and machining method for the composite fiber curtain filtration has the advantages that the effects of printing and dyeing, bending and polishing are achieved, no sizing agent exists, and the cost is low.