In view of the problems of small test size space, poor low-frequency response, and internal and environmental reflection affecting measurement accuracy when the existing specular monocone TEM cell is used as the calibration of pulsed electric field sensors, the standard device of pulsed electric field based on ultra-large low-reflection specular monocone is designed and developed on the basis of simulation optimization analysis by using ultra-large precision single-cone structure, terminal impedance loading and low-reflection special-shaped anechoic chamber. The generatrix of the monocone is 2 m long and can adapt to pulse signals with a pulse width greater than 5 ns, and the amplitude of the standard pulse electric field generated by the device is 50~ 150 V/ m, the rise time of the pulse is less than 100 ps, the pulse width is greater than 5 ns. This standard device meets the needs of large space, wide frequency band and high accuracy calibration equipped with test pulse electric field sensors.