Abstract Band alignment caused by discontinuous band structures of two different materials plays a central role in semiconductor heterojunctions and interface physics. We investigate the electronic structures and band alignments of double-wall MoS₂/WS₂ nanotubes with different chirality and geometry. We find that the band gap of both armchair and zigzag nanotubes obeys E G = E G in − exp − δ Δ R − α , with E G in being the band gap of the inner nanotube and Δ R the spacing distance between the inner and outer nanotubes. When placing MoS₂ in the inner and WS₂ in the outer of the nanotubes, the band alignment belongs to type-I because the conduction band minimum (CBM) of the inner MoS₂ nanotube is lower than that of the outer WS₂ nanotube, and the valence band maximum (VBM) of MoS₂ nanotube is higher than that of WS₂ nanotube. While putting the WS₂ nanotube in the inner and MoS₂ nanotube in the outer, the CBM and VBM of MoS₂ nanotube are both lower than the corresponding band extreme points of WS₂ nanotube when their diameter is small. Therefore, type-II to type-I band alignment transition occurs, originating from charge transfer with increasing spacing distance. Due to the adjustable band gap and electronic structures, we expect that these double-wall hetero-structured nanotubes will have great potential in optoelectronic devices.