Multi-label Intention Understanding (MIU) for images is a critical yet challenging domain, primarily due to the ambiguity of intentions leading to a resource-intensive annotation process. Current leading approaches are held back by the limited amount of labeled data. To mitigate the scarcity of annotated data, we leverage the Contrastive Language-Image Pre-training (CLIP) model, renowned for its proficiency in aligning textual and visual modalities. We introduce a novel framework, Intention Understanding with CLIP (IntCLIP), which utilizes a dual-branch approach. This framework exploits the 'Sight'-oriented knowledge inherent in CLIP to augment 'Semantic'-centric MIU tasks. Additionally, we propose Hierarchical Class Integration to effectively manage the complex layered label structure, aligning it with CLIP's nuanced sentence feature extraction capabilities. Our Sight-assisted Aggregation further refines this model by infusing the semantic feature map with essential visual cues, thereby enhancing the intention understanding ability. Through extensive experiments conducted on the standard MIU benchmark and other subjective tasks such as Image Emotion Recognition, IntCLIP clearly demonstrates superiority over current state-of-the-art techniques. The code and models will be released.