Atherosclerosis is a life-threatening disease of utmost clinical importance, which, despite recent progress in cardiovascular field, is still related to high morbidity and mortality. It is characterized by the accumulation of lipids within the arterial wall that is vulnerable and prone to rupture in pathological cardiovascular changes and acute events. In this paper, for the first time, we proposed a conceptually theranostics method to stabilize the atherosclerosis: Optoacoustic tomography (OAT)/optical coherence tomography (OCT) guided lipid-selective ablation for atherosclerotic plaque. To achieve this theranostics goal, the underlying pulsed laser-tissue interaction mechanisms of OA/OCT theranostics models was investigated for both OAT localization of lipid core as well as pulsed laser power titration for ablation. OCT was used to observe pre- and post-ablation result of fibrous caps and vessel wall, followed by histology validation. The feasibility of OA/OCT was first verified by plaque composition mimicking experiment. Furthermore, ex-vivo mouse aortas containing lipid-rich plaque were imaged and selectively ablated to show the intrinsically registered OA/OCT for targeting lipid core without causing adjacent tissue damage. Our results demonstrated the superiority of this theranostics technique for effective and precise removal of atherosclerotic plaque, which brings new capabilities and photonics insights to cardiovascular medicine.