In order to explore the effect of aromatic compounds on the combustion performance of CMDB propellant， 2，2''''-（propane-1，1-diyl）bis（4-（tert-butyl）phenol） （PDBP） was used to prepare HMX-CMDB propellant， and the combustion performance of HMX-CMDB propellants with different PDBP contents was studied using the target line method. The results showed that with the increase of PDBP content， the burning rate and pressure index of HMX-CMDB propellant significantly decreased. For HMX-CMDB propellant containing 7% PDBP， the burning rate at 16 MPa decreased to 8.55 mm·s^-1， and the pressure index decreased to 0.217. Compared with the sucrose octaacetate （SOA）， HMX-CMDB propellant containing the same mass of PDBP exhibited almost unchanged burning rate in the low-pressure region （8-10 MPa）， a further reduced burning rate in the high-pressure region （12-16 MPa）， resulting in a lower pressure index. In addition， after replacing SOA with 1% PDBP， the detonation heat of HMX-CMDB propellant was reduced by only 20 kJ·kg^-1. Based on chemical structure analysis， the mechanism of PDBP''''s burning rate inhibition effect is as follows： the aromatic molecule decompose to form protons and structurally stable radical molecules with conjugated π bonds， and the active protons can react with the active radicals released from the decomposition of energetic molecules in the HMX-CMDB propellant， forming stable structures that mitigate the autocatalytic effect of free radicals， thereby reducing the burning rate.