Compared with 308 nm excimer laser ,355 nm pulsed solid laser has more advantages in terms of peak power ,cost and convenience. Fresh pig blood clot and fresh chicken tibia block were used as thromboid and calcified tissue to study the tissue ablation characteristics and rules of 355 nm pulsed solid laser. The experimental results show that the morphology of tissue ablation holes is good and there is no particle deposition ; The diameter of particles after ablation is 10 microns ,which is in the range of natural metabolism of human body ,and the smaller the pulse energy is in the range of 25 mJ ~ 200 mJ ,the smaller the particles after ablation ; Under perfusion conditions ,the tissue tempera- ture rise in the heat-affected zone is less than 4. 5 ℃ ,which will not cause thermal damage to the vessel wall. There- fore ,355 nm pulsed solid laser can effectively ablate thrombus and calcified tissue ,and has a good application prospect.