Abstract: The side branch resonance muffler is composed of a main pipeline and a closed pipe connected to it. By constructing a 1/4 wavelength tube, acoustic interference and resonance can be achieved to realize the purpose of noise reduction. This article studies the application of side branch resonators in traditional plate silencers, utilizing the principle of side branch resonators to enhance the low-frequency noise reduction performance of plate silencers. The results of simulation calculations and experimental testing show that the designed 2-meter long plate muffler achieves a noise reduction of 17 dB in the 100 Hz frequency band, and the 0.96-meter long plate muffler achieves a noise reduction of 26 dB in the 200 Hz frequency band. The laboratory test results match the peak noise reduction frequency bands obtained from COMSOL simulations.