Crystal bar hafnium prepared by the iodide process was studied. The influences of three important factors (filament temperature, retort materials and feed types) on the removal of iron from hafnium crystal bar under iodide process were investigated. Results show that the impurity contents of iron in the hafnium crystal bar decreased with the rising K value. Both the retort materials and feed types have obvious influence on the iron impurity contents of hafnium crystal bar. It is proposed that the optimal condition was attained when hafnium turnings was used as feed, stainless steel with molybdenum cylinder liner as retort materials, and K value was at a relatively high level.