Accurate determination for formation age of mafic or ultramafic rocks has long been one of the most difficult scientific problems in isotopic geochronology. Due to much controversy on using the age of zircon as magmatic crystallization age of mafic or ultramafic rocks, a growing number of researchers have turned to obtaining the age of baddeleyite. The approaches commonly used before are thermal ionization mass spectrometry (TIMS) or secondary ion mass spectrometry (SIMS) U Pb isotopic dating. With the entry into the 20th century, some researchers have tried to use laser ablation inductively coupled plasma mass spectrometry (LA ICP MS) technology to obtain age of baddeleyite. However, the method is still at a trial stage and rarely reported as well. Here we summarized previous baddeleyite dating research and proposed a new dating method for age of baddeleyite by LA ICP MS. With this purpose, this study probed into laser condition and parameters of baddeleyite, finally establishing a dating method for baddeleyite using LA ICP MS U Pb. Application of this method in the sample from ultramafic rock in Jinchuan yielded an accurate dating result. Using the principle of “Intercept Method”, we worked out a new data processing program named BUSTER, which then were applied to baddeleyites from Phalaborwa and Jinchuan. The results were compared with those from other data processing softwares such as Glitter and ICPMSDataCal. The results show that BUSTER is better than Glitter and ICPMSDataCal in terms of accuracy but worse in precise, and this may be attributed to the different methods of numerical fitting and error transfer. In addition, this study also carried out SHRIPM analysis for the same sample (baddeleyite) from the Jinchuan complex, and the result has identical errors as the age using the LA ICP MS U Pb method.