Recently, various two-dimensional boron structures have been predicted and some of them have been successfully synthesized. Borophene exhibits significant anisotropy in its electronic band structure, which has potential applications in electronic devices. In this study, a reactive molecular dynamics method was used to investigate the lattice thermal conductivity (LTC) and thermal anisotropy of α′ and α′ − 4H borophene structures at 300 K. The results show that the lattice thermal properties of α′ borophene monolayer are enhanced by hydrogenation along the armchair direction, and the lattice thermal conductivities of both α′ and α′ − 4H structures have high anisotropy. The results revealed that in the armchair direction, the thermal conductivity is increased by increasing the length of the samples while it is decreased for the zigzag direction. Owing to defects in the structure, interference of phonon waves, and phonon dispersion in the zigzag direction, the heat transfer decreases with increasing sample length.