Zr-doped icosahedral Cu nanoparticle (NP) with 54 Cu atoms and one Zr atom is studied by Density functional theory (DFT) calculation for CO2 reduction to CHO which is intermediate converting into methanol. A Cu atom being at the vertex (′v′) and edge (′e′) site of Cu NP’s surface is respectively substituted by a Zr atom, and this doping of Zr atom makes Cu NP becoming one of the potential catalysts for CO2 reduction to methanol. Especially, Cu54Zre NP shows it’s superior activity and selectivity for CO2 reduction to CHO, where Zr atom stays at ′e′ site. This can be well confirmed not only from it’s adsorption behavior for several important intermediates, but also from the lowered reaction barrier of CO2 converting into CHO. Moreover, Cu54Zrv NP also shows it’s relatively good performance in CO2 converting into CHO, where Zr atom is doped at ′v′ site, if compared with pure Cu NP and even bulk Cu with Zr doping. That is to say, the introduction of Zr atom can effectively improve the catalytic properties of Cu NPs for CO2 reduction to methanol, and the fact of Zr atom doping site and it’s relation with catalytic property, to some extent provides the guidance in designing catalysts that capture and convert CO2 to fuels or chemicals.