Building a crude phenol purification unit eliminates impurities including water, acetone, alpha-methylstyrene and other organic byproducts. Three mainstream purification technologies are available: vacuum distillation, extractive distillation and melt crystallization. Vacuum distillation reduces operating temperature to avoid phenol thermal degradation; extractive distillation adopts selective solvents to separate close-boiling mixtures; melt crystallization leverages freezing point differences for high-purity output with low energy consumption. Combined multi-technology advanced processes can produce high-grade phenol up to 99.9 wt%, which meets strict requirements for bisphenol-A, phenolic resin and other fine chemical production. The integrated process cuts waste discharge, upgrades product quality and boosts overall plant economic benefits.