This article utilizes first‐principles calculations within the density functional theory framework, employing spin generalized gradient approximation, to investigate the spin polarization of arsenic nitride nanotubes (AsNNTs). It is found that AsNNT does not exhibit spin polarization and has a bandgap of 1.05 eV, indicating that it is a semiconductor. Decoration with C, O, Ge, and Se on AsNNT induces spin polarization, resulting in magnetic moments of 1.001, 0.916, 0.770, and 0.967 μB, respectively. Meanwhile, all decorated configurations exhibit narrow bandgap semiconductor properties. Furthermore, the nonequilibrium Green's function method is used to study the spin‐polarized current of AsNNT decorated with C, O, Ge, and Se. It is found that AsNNTs decorated with C, Ge, and Se have relatively small spin current values. Notably, the Se‐decorated AsNNT exhibits the highest degree of spin polarization, with the spin current being nearly fully polarized.