A harmonic beam splitter with a simply regular structure and good optical characteristics was designed by adding matching layers between the basic stack and its media and optimizing with a computed-aided film stack design procedure. Coatings were deposited on K9 glass substrates by electron beam evaporation and photoelectric maximum control method, and then annealed in air at 260 ℃ temperature for three hours. The optical properties of coatings were characterized with a Lambda 900 spectrophotometer, the weak absorption of coatings was measured by surface thermal lensing technique (STL), and laser-induced damage threshold (LIDT) was assessed using 1064 nm Q-switch pulsed laser at a pulse length of 12 ns. It was found that a good agreement between the theoretical and the experimental transmittance was obtained, there was almost no shift for the center wavelength after annealing at 260 ℃, which showed the sample had a good temperature stability, the absorption of the coating decreased after annealing, and a remarkable increase of LIDT was found with the decrease of absorption. The experimental results as well as the theoretical ones indicated that it was a good method to add matching layers to the basic stack for a harmonic beam splitter at 1064 nm.