A method for preparing arginine deimidase by recombination. The invention discloses a preparation method for recombinant expression of ArginineDeiminase (hereinafter referred to as ADI) by escherichia coli, mainly including a recombinant expression method and an inclusion body renaturation method using urea as a denaturation agent. The N terminal of ADI prepared by recombination expression does not contain methionine.