The technology of laser-focused atomic deposition can be used to develop the nanostructure transfer standard of length. In this paper, a novel method is used to fabricate the nanometer structure through chromium atomic deposition. By the designed pre-collimated hole with three apertures, the chromium atomic beam may be divided into three parts. The middle part is for the atom beam to react with the standing wave and the deposition on the substrate with periodic distribution and the other two parts which can not be blocked by the substrate are for the atom beam to react with the detecting laser beam, and can be used to inspect the characteristic of atomic beam. This can provide some guidance for the progress of deposition. The simulatiion results show that the full width of half maximum is 6.2 nm and the contrast is 28:1 by using this special pre-collimated hole. On the other hand, the full width of half maximum and contrast are 32 nm and 8∶1 without using this special hole.