A radio-frequency ablation clamp is provided with a holding portion, an expansion link, a clamp arm and a clamp body, wherein the clamp body is straight or cambered, and 5-7 cm long; and an included angle between the clamp body and the clamp arm is 90-110 degrees. The invention also provides an application of the radio-frequency ablation clamp as a medical instrument in venous ablation of atrial fibrillation treatment. According to the preceding medical device, the radian of the clamp body, the size of the opening of the clamp body, the angle of the clamp body with the clamp arm and the length of the clamp body are improved, so that the problems of the radio-frequency ablation clamp encountered in operation applications are solved and the radio-frequency ablation clamp well meets the requirements in operation. In use of the radio-frequency ablation clamp, only one radio-frequency ablation clamp is needed to complete double-side venous ablation; therefore, the number of the radio-frequency ablation clamp used can be reduced and the operation cost can be also saved for a patient. Besides, the radio-frequency ablation clamp is used with a new atrial fibrillation treatment operation method, so that the operation effect can be improved and operation wounds can be reduced.