Abstract: Proposed here in the article is an optimized measurement method for the oil pipe thread crest diameter and ovality is proposed.And a geometric model for measuring the thread crest diameter is established.The design thinking of the said optimized measurement method is analyzed,and the specific calculation formula is deduced.With the said method,just three operations of measurements can get the result approaching the maximum and minimum values of thread crest.Compared with the currently-used four point measurement method,the six point measurement method and full circumference measurement method,the said optimized measurement method can improve the measurement efficiency,while the measurement accuracy is guaranteed,being worth widely applying to testing as made on the oil pipe-making site.