A 5G MIMO antenna structure includes a PCB and more than one first antenna assembly arranged on the PCB at intervals. Each first antenna assembly includes a feed branch, a first radiator and two second radiators, wherein the first radiator and the two second radiators are coupled to the feed branch, the first radiator is of an inverted U-structure and has two tail ends connected to grounding points of the PCB, the feed branch is located in the first radiator and corresponds to a feed point of the PCB in position, and the two second radiators are arranged in the first radiator, connected to the first radiator, and respectively located on two sides of the feed branch. The 5G MIMO antenna structure has a good radiation effect, a good isolation effect and a smaller size, and can meet the usage requirements of a 5G system below 6 GHz.