In this paper, we propose a new structure of 4H-SiC-based ESD(Electrostatic discharge) protection device with low on-resistance and excellent high-temperature characteristics while improving trigger technology by applying floating technology. By TLP measurement, the characteristics were analyzed compared to the conventional GGNMOS. In addition, a method to improve the snapback characteristics of the proposed device with design variables was introduced. As a result, a device with improved snapback characteristics and improved reliability in 70 V applications was proposed.