The cell nucleus, as the central hub of cellular physiological activities, represents an effective target for cancer therapy. Targeting strategies aimed at the cell nucleus can enhance the delivery of more drugs into the tumor cell nucleus, thereby improving therapeutic efficacy. Such approaches can overcome the limitations of previous tissue- and cell-level treatments, such as insufficient specificity and excessive toxic side effects. Currently, researchers have integrated carbon nanoparticles (CNPs), therapeutic molecules, and nucleus-targeting components to construct various nucleus-targeted carbon nanoparticle delivery systems for tumor imaging and treatment. These systems not only increase drug concentration within the cell nucleus but also enable certain CNPs to utilize their intrinsic fluorescence for imaging monitoring. This review summarizes the latest classification progress of nucleus-targeted CNPs, their mechanisms of action in cancer-targeted diagnosis and treatment, and their applications in cancer therapy. Additionally, the article discusses the current challenges and future directions in this field, aiming to provide valuable reference information for precision cancer treatment.