Metal-organic frameworks (MOFs) have attracted extensive research attention owing to their structural tunability and functional versatility. In particular, magnetic MOFs have emerged as promising candidates for spintronic applications recently. However, inherent challenges still remain for their practical applications, such as low magnetic transition temperature and small saturation magnetization. Herein, we propose a Co doping strategy to modulate the magnetic properties of Fe-based MOFs. A series of mixed metal MOF materials, namely Co_xFe_1-x-BDC (x = 0, 0.1, 0.5, 1), were synthesized on the MOF-5 framework using a solvothermal method. X-ray diffraction and X-ray photoelectron spectroscopy results verify the well-defined crystalline structure of the obtained Co_xFe_1-x-BDC samples. Scanning electron microscopy images reveal distinct morphological differences between Co-BDC and Fe-BDC, while the doped samples (x = 0.1, 0.5) exhibit morphologies similar to the Fe-BDC. The magnetic performances of all samples were systematically measured from 300 K to 2 K. Magnetic hysteresis loops and temperature-dependent magnetization curves demonstrate that Co-BDC undergoes a magnetic phase transition at 27 K and exhibits spin-canted antiferromagnetism at low temperatures, whereas Fe-BDC presents weak ferromagnetism at low temperature. Notably, Co doping is proven to effectively enhance the coercivity and saturation magnetization of Fe-BDC. Particularly, the Co_0.5Fe_0.5-BDC exhibits prominent ferromagnetic behavior at low temperatures. Based on experimental results, an ordered substitution model is proposed, in which ordered alternating stacking of Co and Fe ions is present in Co_xFe_1-x-BDC. First-principles calculations further suggest the formation of local short-range ordered Co/Fe atomic arrangement. A strong p–d spin-polarization coupling is shown between the Co 3d and O 2p orbitals. Moreover, high-concentration Co doping induces long-range magnetic ordering. This work reveals the magnetic enhancement mechanism of mixed-metal MOFs and provides a feasible strategy for the design of magnetic MOF materials for spintronics.