The invention relates to a radio frequency ablation catheter and system. The radiofrequency ablation catheter comprises an ablation catheter body with an ablation coil, the ablation catheter body comprises a catheter body, and the catheter body sequentially comprises a guide wire tube, a main body tube, a coil sleeve, a coil and an insulating outer sleeve from inside to outside; and the guide wire tube is arranged in the catheter body, the main body tube and the guide wire tube are bonded at the far end to form a hemispherical smooth end part, the coil sleeve sleeves the main body tube, the insulating outer sleeve is thermally shrunk outside the coil, and sealing sleeves are further arranged and thermally shrunk at two ends of the insulating outer sleeve. A gap for placing a thermocouple is formed in the coil formed by winding an ablation line. The catheter structure has high sealing safety, and the temperature measurement accuracy is remarkably improved. In addition, the coil is arranged to be multiple sections, each section of coil is provided with at least one thermocouple used for segmented temperature control, and the temperature control accuracy and the radiofrequency ablation efficiency are improved. The invention also provides a wiring mode of a plurality of coils, so that the product is safe and effective.