Despite the increasing number of coronary interventions in China, long-term adverse cardiovascular events remain high, especially in patients with acute coronary syndromes (ACS). The advent of intracoronary imaging and coronary physiological diagnostic techniques, such as optical coherence tomography (OCT), intravascular ultrasound (IVUS), near infrared spectroscopy (NIRS), and flow reserve fraction (FFR), has optimized the diagnosis and risk classification of patients with ACS. Intracoronary diagnostics compensate for the deficiencies of conventional coronary angiography in identifying and incriminating lesions and high-risk lesions. The combination of intracoronary imaging and physiological techniques is expected to achieve a comprehensive evaluation of the structural features and physiology of the coronary arteries, thus further tailoring and improving the prognosis of patients.