Despite advancements in diagnostic methods and therapeutic strategies, the mortality rate of hepatocellular carcinoma (HCC) remains as high as its incidence rate. Most liver cancers are detected in the advanced stages, when treatment options are limited. Small HCC is difficult to diagnose and is often overlooked by current imaging methods because of the complexity of the liver environment, especially in cirrhotic livers. In the present study, we developed a tumor “cruise missile”, mesoporous Fe3O4-containing glucose oxidase-conjugated GPC3 peptide nanoparticles (FGP NPs). It was designed to enhance the accuracy of small HCC visualization to 85.7% using combined ultrasound/photoacoustic imaging in complex liver environment, which facilitated sequential catalytic targeted therapy for small HCC. In a carcinogen-induced mouse HCC model, FGP NPs could be used to accurately diagnose HCC in a liver cirrhosis background as well as distinguish HCC nodules from other abnormal liver nodules, such as cirrhosis nodules and necrotic nodules, by dynamic contrast-enhanced photoacoustic imaging. In a mouse xenograft HCC model, highly reactive oxygen species were formed by sequential catalytic reactions, which promoted HCC cell apoptosis, significantly increasing the survival of the model mice. The present study provides a basis for the precise detection and elimination of small HCCs in the complex liver environment.