This paper presents the design of a D-dot monitor for measuring nanosecond high voltage pulses, including the design, simulation, and experiments of the probe and integrator. The electrode of the probe can be replaced and its axial length can be adjusted according to different measurement requirements. The structure of the probe is optimized according to the results of simulation on electrostatic field by CST. The amplitude-frequency response of the monitor is simulated by Pspice to ensure that the operating frequency of the monitor meets the design requirements. The D-dot monitor is applied to measure the high voltage pulses with nanosecond level pulse width. The experimental results show that the D-dot monitor meets the measurement requirements for high voltage pulses with rise time of about 37 ns and voltage amplitude of about 597 kV.