Abstract: Chalcopyrite has antiferromagnetic properties, and the magnetic setting is very important for the accuracy of the calculation when using density functional theory (DFT) method. In addition, the correction of the Hubbard U value for the Fe 3d orbital with strong electron correlation is also very important for the correct electronic structure. The effects of ferromagnetism, antiferromagnetism and Hubbard U correction on the density functional theory of chalcopyrite were studied. The results showed that the lattice constant deviated far from the experimental value when the U value was not used, and the lattice parameters and band gap of chalcopyrite were very close to the experimental value only when the U value of 2.0 eV and antiferromagnetism were set simultaneously. Without magnetic setting, the surface structure relaxation was large, and ethyl thiocarbamate (Z-200) could not adsorb on the surface. The effect of ferromagnetic setting on the structural relaxation of Cu atoms was greater than that of Fe atoms, and the effect of antiferromagnetic setting on the relaxation of these two metal elements was the same, both of which were approximate plane structures after bonding with S. In addition, the adsorption of Z-200 on the ferromagnetic surface was weaker than that on the antiferromagnetic surface. The results show that the antiferromagnetic setting and Hubbard U correction are very important for density functional theory calculation of chalcopyrite. This study provides a reference for density functional theory calculation of chalcopyrite.