Abstract: The angular multiplexing technology is used in the Heaven-Ⅰ high power KrF excimer laser facility to amplify the six short light pulses. The complex optical system results in wasting time and labor in the beam path adjusting and the high precision manual adjustment is very difficult. Because of its deep UV wavelength of 248 nm, the automatic collimation technology commonly used is not suitable for the Heaven-Ⅰ. In order to satisfy the requirement of the laser-matter interaction experiment, a new automatic collimation technology suitable for the Heaven-Ⅰ is necessary to be developed to improve the coincidence accuracy of the focal spot. In the paper, aiming at the three-beam propagation through the preamplifier, the automatic collimation technology suitable for Heaven-Ⅰ was studied and used in the three input and output laser beams of the preamplifier. The result shows that the automatic collimation system can realize the fast and high-precision adjustment, which sets up the technology foundation for automatic collimation of Heaven-Ⅰ high power KrF excimer laser facility.