The invention relates to a tissue ablation, cutting and merging system. The tissue ablation, cutting and merging system comprises a handle assembly, a shaft assembly, a working part, a circuit systemand a power source, wherein a trigger switch is arranged on a controller of the circuit system; a trigger part is arranged on a trigger; when the trigger moves in the direction facing a gripping handle of a housing until a force limiting mechanism works, the trigger part touches the trigger switch to switch on the trigger switch; and when the trigger moves in the direction away from the gripping handle of the housing, the trigger part is separated from the trigger switch to switch down the trigger switch. According to the tissue ablation, cutting and merging system disclosed by the invention,the trigger switch can only be switched on when the force limiting mechanism works, so that the tissue ablation, cutting and merging system disclosed by the invention can perform tissue ablation, cutting and merging under a set working pressure, the operation effect is more stable, accidental injury which is possibly caused by misoperation and clinical effect differences of vascular occlusion, tissue ablation, tissue cutting and the like caused by different clamping force used by different surgeons are effectively avoided, and the tissue ablation, cutting and merging system is safer and more effective.