A microstrip ultra-wideband antenna is provided, including: an upper dielectric substrate, a radiation patch, an open-circuit line, a short-circuit line, a ground plane, a lower dielectric substrate, a vertical dielectric substrate, isolation walls, a hyperbolic microstrip balun feeder and an ideal wave port. The radiation patch is attached to a lower surface of the upper dielectric substrate; the ground plane is attached to an upper surface of the lower dielectric substrate; the short-circuit line and the open-circuit line are attached to a rear surface and a front surface of the vertical dielectric substrate respectively; the hyperbolic microstrip balun feeder is attached to the front and rear surface of the vertical dielectric substrate; the isolation walls are located between the upper dielectric substrate and the lower dielectric substrate perpendicularly to an end of the radiation patch; and the ideal wave port is provided below the hyperbolic microstrip balun feeder.