This paper proposes a HV (high-voltage) level shifter to shield the dV/dt noise. When there is the dV/dt noises, the proposed level shifter’s output is locked by the dV/dt noise shielding circuit. So, the proposed level shifter has infinite dV/dt immunity, which is not affected by the supply voltage, and processes. In the 0.5µm BCD process, the proposed level shifter is simulated, realizing the ±250V/ns dV/dt noises shielding function and less than 1.5ns delay time under the 400V HV power supply.