In current camphor-synthesizing industry, industrial camphene is used as raw material to synthesize up iso-camphol by esterifying saponification or direct hydration.This invention discloses a process to purify camphor, which features that after dehydrogenating iso-camphol, appropriate boric acid is added according to the quantity of impurities to remove them, and then the alkaline matter such as calcium oxide is added in for neutralization, thus obtaining a synthetic camphor with 98-99% of purity.