Abstract: A coaxial pulse voltage probe is designed to measure the signal through the input of TEM cell or GTEM cell in calibrating electromagnetic pulse(EMP) sensors. The output differential signal of the probe can be converted by numerical integration to obtain the measured EMP field, and the measurement sensitivity can be adjusted. The peak E-field distribution and the port characteristic impedance of the probe with different monopoles are simulated and compared. A spiry monopole is selected according to the simulation. Experiment verification is carried out. The frequency response and the sensitivity of the fabricated prototype coaxial probe are measured. The variation of sensitivity coefficient with the distance between the spiry monopole and the inner-conductor center is obtained. The simulation and the experiment indicate that the spiry monopole has very small perturbation to the inner field and the impedance of the coaxial probe. This kind of probe can be used in the measurement and calibration of EMP with rise time of nanosecond level.