An ultra wide band antenna structure and an electronic device. The ultra wide band antenna structure includes: a dielectric substrate; an antenna structure, located on a side of the dielectric substrate; the antenna structure includes a radiation patch and a feeder line; and a ground layer, located on a side of the dielectric substrate facing away from the antenna structure; the radiation patch has a first hollowed-out slit, and a length of the first hollowed-out slit is related to λ/2; and λ represents a wave length in a frequency band of a needed notch wave.