The conventional photoelectric detector can not get the laser signal because of the laser’s high energy and long wavelength.To achieve the goal of real-time monitoring the laser beam and fast aligning the high-energy laser launching system accurately,we monitored the output mirror of laser resonator to supersede the laser beam in this paper.In the same way,with a right-angle reflector,the launching system was aligned using the He-Ne laser of beam monitoring system instead of high-energy laser.In the end,the precision of the CO₂ laser launching system was analyzed to inspect the method.The analysis results show that the parallelism errors can reach 15.9″,which satisfies the requirement of system.