A preparing method of coconut charcoal fiber is disclosed. The method includes (1) a step of preparing master batch, namely a step of recovering waste coconut shells, extracting coconut shell cellulose by dipping, beating, removing impurities and airing, heating the coconut shell cellulose to 1200 DEG C, performing high-temperature carbonization to prepare coconut charcoal, smashing the coconut charcoal into nanometer powder by utilization of a particle collision principle and through a dry grinding manner, adding anionic antistatic agent powder into the coconut charcoal powder, and fully mixing to obtain the coconut charcoal master batch, and (2) a step of spinning the coconut charcoal fiber, namely a step of preparing the hollow type coconut charcoal fiber with a three-dimensional crimp configuration by melt spinning, drawing, sizing, crimping, oiling, cutting and packaging. The prepared coconut charcoal fiber has good antibacterial, far infrared and anion-releasing performances, and the like, and accords with functional, healthy and environment friendly ideas pursued in product development. For better application in development of home textile products, the antistatic property of the fiber is improved by adding the antistatic agent, thus improving product quality.