Abstract: This paper introduces an innovative four-port, low-coupling Multiple-Input Multiple-Output (MIMO) antenna design based on metamaterials, aiming to achieve high-performance applications in MIMO systems. In the antenna design, split ring resonators (SRR) are integrated around the feed lines, while complementary split ring resonators (CSRR) are etched onto a cross-shaped ground plane layer. The synergistic effect of these two structures significantly enhances the antenna's isolation performance near the 3.8 GHz and 5.8 GHz frequency bands. Through the effective regulation of the electromagnetic field distribution by the metamaterial structures, the design not only reduces electromagnetic coupling between ports but also maintains the antenna's radiation performance. Simulation results indicate that the antenna achieves an isolation of better than -19 dB in the 3.8 GHz band and better than -25 dB in the 5.8 GHz band, while also exhibiting good impedance matching and stable radiation patterns within the operating bands, meeting the communication requirements for 5G, WiMAX, and Wi-Fi frequency bands.