Materials with excellent magnetocaloric properties are a key factor for the application of magnetic refrigeration technology. In this work, an amorphous ribbon of quaternary Gd₄₅Ni₃₀Al₁₅Co₁₀ alloy is designed and prepared, and the magnetocaloric properties of the alloy are systematically studied. The introduction of Co can improve the thermal stability of the amorphous structure. The Curie temperature and effective magnetic moment of Gd₄₅Ni₃₀Al₁₅Co₁₀ amorphous ribbon are 80 K and 7.21 μ_B, respectively. At 10 K temperature, the saturation magnetization and the coercivity of the alloy reach 173 A·m²·kg^–1 and 0.8 kA·m^–1, respectively, which indicates excellent soft magnetic properties. At 5 T magnetic field, the peak value of magnetic entropy change and relative cooling capacity of Gd₄₅Ni₃₀Al₁₅Co₁₀ amorphous alloy are as high as 10.2 J·kg^–1·K^–1 and 918 J·kg^–1 respectively. The amorphous alloy has typical secondary magnetic phase transition characteristics, and the magnetic refrigeration can be realized in a wide temperature range. The Gd atomic content is less than 50% with low cost, which means that the alloy is an ideal magnetic refrigeration material.