A high-voltage normally-off AlGaN/GaN hybrid-gate HEMT (HG-HEMT) with high current-density and low on-resistance on Si substrate is fabricated. The proposed device features a hybrid-gate consisting of a short E-mode gate and a long D-mode gate. In the off-state, the short E-mode gate confirms the normally-off operation, while the D-mode gate can clamp the channel potential at a low drain voltage, which delivers high blocking capability. In the on-state, the short E-mode channel and the D-mode channel providing lower channel resistance facilitate high on-current or low on-resistance. Therefore, the HG-HEMT achieves a high breakdown voltage and low on-resistance simultaneously. Compared with the conventional device, the HG-HEMT is shown to deliver comparable breakdown voltage while featuring 62% lower on-resistance.