Abstract: The acoustic transmission loss model of multi-branch HQ tube is established based on the wave equation. The proposed model can be used to calculate the HQ tube model with any number of branches, different diameters and/or lengths. The effectiveness of the method is verified by comparison with previous calculations. Then, the influence of different physical parameters, such as the length and diameter of HQ tube and the number of HQ tube branches, on the acoustic transmission loss of multi-branch HQ tube is analyzed and discussed in detail. The calculation results show that the acoustic transmission loss of multi-branch HQ tube is the same as that of a single-branch HQ tube when the total cross-section areas of both are equal; and changing the length of the HQ tube can change its resonance frequency. By comparing the average acoustic transmission loss in frequency domain, it can be seen that the acoustic performance of the HQ tube structure with different lengths is superior to that with united length.