Abstract: Abstract: Objective Aiming at the problems such as compact layout of shipboard wireless communication equipment, limited space, and serious electromagnetic interference between equipment, a miniaturized ultra-wideband Multiple-Input Multiple-Output (UWB-MIMO) antenna with high isolation is proposed. Methods The antenna bandwidth was extended and the antenna return loss was increased effectively by cutting Angle design and etching offset triangle hole. The Complementary Split-Ring Resonator (CSRR) is used to enhance the MIMO antenna isolation and add resonant frequency points to achieve ultra-wideband. At the same time, the porous parasitic patch is loaded on the floor to effectively reduce the coupling at high frequency of the antenna. Results The simulation and measured results show that the overall size of the antenna is very small, only 28mm×17mm×1.6mm, the operating bandwidth of the antenna is 4.6~10.9GHz, the relative bandwidth is 81.3%, and the coupling coefficient in the frequency band is lower than -15dB, and the maximum is -30.7dB. The envelope correlation coefficient of the antenna is ECC<0.008, and the gain in the whole band is >2dB. Conclusion The MIMO antenna is compact in size, covers ultra-wide band and has good omnidirectional characteristics, which can be widely used in shipborne small wireless communication equipment.