Abstract: An improved cutting technics of steel pipes of offshore platform was researched based on the fact that domestic pipe cutting machines are generally equipped with cutting torches which rotate around twoaxis today. Instead of the traditional cutting technics which is obsolete and based on an approximate cutting method with cutting torches rotated around single axis several years ago, this new technics applies an accurate geometric modeling method which results in an accurate cutting technics instead of approximate technics obtained by traditional approximate modeling method. The software simulation shows that, compared with traditional approximate cutting technics, this accurate technics, implemented by a cutting torch which rotates around two axises, can effectively reduce the cutting length so as to improve the cutting speed and time efficiency. Besides, the surfaces match better while being welded together as the accurate cutting technics fully follows the geometric properties of surfaces.