The invention discloses a forming method for a high-resolution channel pattern. The forming method comprises the following steps: providing a semiconductor substrate and forming a target material layer, a first hard mask layer, a second hard mask layer, a first bottom anti-reflection layer and first photoresist on the semiconductor substrate in sequence; forming a first photoresist main pattern and a first photoresist side-lobe pattern in the first photoresist through first photo-etching; forming the first main pattern and the first side-lobe pattern in the second hard mask through etching; coating a second photoresist on the second hard mask layer; forming a second photoresist main pattern and a second photoresist side-lobe pattern in the second photoresist after second photo-etching, wherein the second photoresist main pattern is positioned above the first side-lobe pattern region, and the second photoresist side-lobe pattern is positioned above the first main pattern region; and etching and transferring the first side-lobe pattern and the second photoresist side-lobe pattern to the target material layer by using a self-alignment technology to form the channel pattern. According to the forming method, a channel pattern with small line width is formed, so that the resolution of the channel pattern is improved.