H I mass-halo mass relation at two different redshifts. Upper (lower) panel: H I mass-halo mass relation at z = 0(0.66). The total H I mass is shown as a blue curve, the contribution from central galaxies is shown in orange and the contribution from satellite galaxies is shown in green. Regardless of whether it is at z = 0 or 0.66, the central galaxy always contributes the most H I mass to low-mass halos, and satellite galaxies contribute most of the H I mass in high-mass halos. We also show the observed H I mass-halo mass relation as red dots at z = 0 (Guo et al. 2020) for comparison.