The phenomenological Ginzburg-Landau model with two order parameters appears in many works of D.V. Shopova and D. I. Uzunov. Here, we develop a microscopic approach that, on the basis of mean-field theory and the functional integral formalism, establishes the two-component Ginzburg-Landau functional to show the correlation between the ferromagnetic and the triplet superconducting order parameters. The meanings of the constants encountered in the phenomenological theory are clarified.