Disclosed are an MIMO antenna, a terminal and a method for improving MIMO antenna isolation. The MIMO antenna comprises at least two single antennas arranged on a printed circuit board (PCB); the single antenna comprising: an antenna support, a feeding grounding branch node used for shielding low-frequency coupling between the single antennas, a feeding point, a grounding point and an antenna radiation part, wherein the antenna support is arranged on the PCB, and the antenna radiation part is arranged on the antenna support; and the feeding grounding branch node is connected with the antenna radiation part via the feeding point and the grounding point.