Abstract: Wellbore collision may bring the potentially catastrophic results to human and environment. The wellbore anti-collision technology in order to reduce such accidents is difficult to meet the current needs of field drilling. Through the analysis of present anti-collision technology based on the trajectory measurement and calculation theory and practice, four factors could be concluded causing the failure of wellbore anti-collision, which were big data error of survey steering, low accuracy or loss of adjacent well trajectory data, over-idealized path matching method, and defect of scanning method for anti-collision. The well trajectory matched by the low accuracy parameter and the over-idealized matching method could not meet the actual one. Therefore, the concept of active anti-collision was put forward, and it could be the development tendency of anti-collision technology in the future. Three possible active anti-collision programs were listed, which were acoustic wave detection anti-collision program, electromagnetic wave detection anti-collision program, and ray detection anti-collision program. And the principle and the advantages and disadvantages of the programs were illustrated.