The invention provides an ablation catheter and an ablation system. The ablation catheter comprises a rod-shaped controller, an outer catheter body and a balloon, wherein the outer catheter body comprises a first tube body and a second tube body, the first tube body is fixedly connected with the far end of the rod-shaped controller, the second tube body sleeves the rod-shaped controller, the rod-shaped controller can move relative to the second tube body in the axial direction of the second tube body, the balloon is arranged outside the rod-shaped controller, the near end of the balloon is fixedly connected with the second tube body, and the far end of the balloon is fixedly connected with the first tube body. When the rod-shaped controller moves relative to the second tube body in the axial direction of the second tube body, the distance between the far end of the second tube body and the far end of the first tube body can change, the balloon can deform under the traction of the firsttube body and the second tube body, and therefore the shape of the balloon can be adjusted, the adaptability of the balloon to the shapes of different target blocked objects can be improved, and theblocking effect of the balloon can be improved.