The present disclosure provides a method for preparing a semiconductor device structure with fine patterns at different levels. The method includes forming a hard mask material over a substrate; etching the hardmask material to form hard mask pillars; forming spacers over sidewall surfaces of the hard mask pillars; etching the hard mask pillars and the target material by using the spacers as a mask to integrally forming a plurality of target structures, a high-level recesses in one of the plurality of target structures and a low-level recess between two target structures; and integrally forming a high-level conductive pattern in the high-level conductive pattern and a low-level conductive pattern in the low-level recess.