A novel $\beta$-Ga 2 O 3 Schottky barrier diode (SBD) with a self-aligned shallow groove (SG) and dual field-plate is proposed. The peak electric field around anode is suppressed by the self-aligned SG and dual field-plate. Compared with a conventional SBD, the breakdown voltage $(V_{br})$ of the novel device increases from 400V to 2200V, and the specific on-resistance $(R_{0\text{n},\text{sp}})$ increases from $4.1\text{m}\Omega\cdot\text{cm}^{2}$ to $4.4\text{m}\Omega\cdot\text{cm}^{2}$. The power figure of merit $(V_{\text{br}}^{2}/R_{\text{on}\cdot\text{sp}})$ is $1.1\text{GW}/\text{cm}^{2}$. The variable temperature IV test shows that the prepared device has good temperature characteristics. These results suggest that a self-aligned SG and dual field-plate, composite terminal structure is an effective method with which to improve the performance of a $\beta$-Ga 2 O 3 .