Objective To explore the efficiency of ultrasound combined with dodecafluoropentane (DDFP) phase-change nanoparticles in the thrombolytic therapy, and to evaluate the effectiveness and the biological safety of the treatment in acute myocardial infarction (AMI). Methods Carotid artery blood of the rabbits were prepared into pieces of 0.2ml thrombus. The DDFP nanoparticles were prepared by acoustic emulsion method. There were three groups in the experiment: poly butylene succinate buffer (PBS) as blank control (Group A), SonoVue microbubbles as Group B and DDFP phase-change nanoparticles as Group C. Thrombus in all three groups were placed into an artificial blood vessel model in an extracorporeal thrombolysis simulator combined with low intensity focusing ultrasonic instrument (LIFU) irradiation. Different parameters (time, power, etc.) of LIFU were optimized regarding to the biosafety with LIFU and nanoparticles. The size of the nanoparticles was detected by Malvern laser granulator. The weights and pathological presentations were compared before and after thrombolysis. Cell counting kit-8 (CCK-8) were used to evaluate the survival rates of human umbilical vein endothelial cells (HUVECs) with different concentrations of nanoparticles and different parameters of LIFU. Results The average size of DDFP nanoparticles was(542.6± 28.4)nm. Fluorescence microscopy showed that the structure of nanoparticles was stable and uniformed in size. When the parameters of LIFU were adjusted to 20min in irradiation time and 6W in power, the phase transformation rates, thrombolysis efficiency and the survival rates of HUVECs were higher than those of other conditions. HE-staining slides showed that the number of red blood cells and platelets decreased significantly after thrombolysis in group C, also the texture and structure were softer and looser. Conclusion LIFU combined with DDFP phase-change nanoparticles can effectively dissolve coronary thrombosis. This novel treatment is not only efficient, but also better for biosafety, which has the potential to provide a new treatment for acute myocardial infarction.