SiC Schottky barrier diodes (SBDs) are sensitive to single event burnout (SEB) caused by the high-energy particle strikes, which greatly restricts their applications in the aerospace field. In this paper, we investigate the SEB performance of SiC SBDs with the electro-thermal coupled simulation model using the Sentaurus TCAD simulator. The simulation results show that reducing the reverse voltage can improve the SEB robustness because of the lower impact ionization rate and current density at lower reverse voltage. Based on this, we propose a novel SEB hardening technique of connecting two SiC SBDs in series. Since the voltage across the diode which is hit by the heavy ion can transfer to the other diode in time, the peak temperature attained is greatly reduced, and the SEB robustness is effectively improved for the hardening structure. Due to the low on-state resistance and power dissipation of SiC SBDs, the doubling of the on-state resistance for the series structure will not be a problem. In addition, with the advantages of simple implementation and strong recoverability, the hardening structure proposed in this paper is expected to be applied in practice. • A novel single event burnout hardening technique for SiC Schottky barrier diodes has been proposed. • The SEB robustness of SiC Schottky barrier diodes is effectively improved for the hardening structure. • The hardening structure has no special processing requirements and is easy to implement.