A method and apparatus for preparing boron nitride nanotubes (BNNTs) according to an embodiment may ensure mass-production, may increase yield by reducing a production time, and may prepare BNNTs with high purity. The method includes steps of providing a first powder including boron, forming a second powder including a boron precursor by nano-sizing the first powder, forming a precursor disk by mixing the second powder with a binder; and growing BNNTs on the precursor disk.