A new ultra-wideband±45°dual-polarized microstrip patch antenna based on L-probe coupling feed was proposed. The antenna used orthogonal dual-L-probe coupling feed to achieve dual-line polarization. The channel capacity of the antenna was improved. The electromagnetic simulation software Ansoft HFSS 15.0 was used to complete the simulation verification of the antenna. The coincidence impedance bandwidth of the antenna was 38%, VSWR(voltage standing wave ratio)≤2 between 3.95GHz and 5.80GHz. Moreover, the average gain of the antenna when the two ports are separately excited is greater than 9.0dBi. The isolation between the two ports is greater than 22dB and the cross-polarization level is less than -15dB. The antenna structure is simple in design and can be widely used in C-band ultra-wideband wireless transceiver communication systems.