This article presents the design and fabrication results of 4H-SiC Schottky barrier diode (SBD) with a main P-epilayer island termination. The device simulations analyzed structural parameters, including the island thickness (TMP), inclination angle (θ), length (LMP), and end relaxation length (LER), on electric field distribution within SBD. Additionally, the influence of the P-type doping concentration (DMP) on the breakdown voltage indicates that the main P-epilayer island structure exhibits a relatively wide tolerance range. Using optimal parameters and ion-implantation-free fabrication process, the fabricated SBD with the main P-epilayer island achieved a breakdown voltage of 1543 V with a leakage current of only 1.5 μA under a reverse voltage of 1200 V, and a forward voltage drop (VF) of 1.35 V at a forward current of 10 A using the structural parameters of θ = 20°, LMP = 104 μm, TMP = 1.2 μm, and DMP = 6 × 1017 cm−3.This optimized design brings enormous potential for the low-cost development of SBD.