The chemical structure parameters of trimethylolethane trinitrate (TMETN) were confirmed by analyzing the thermal decomposition characteristics of TMETN. The burning rates and pressure exponents of insensitive and low signature propellants containing TMETN were simulated. The relationship between TMETN content and combustion characteristics of insensitive and low signature propellant containing TMETN was given. And the effect of certain type of organic potassium salt used as flame suppressor (KD) on the burning rate was also discussed. The numerical simulation result shows that calculation results are basically in agreement with test results. The burning rate of insensitive and low signature propellant containing TMETN decreases and pressure exponent of this type of propellant decreases with TMETN content increasing. KD can improve the burning rate of this type of propellant and can help “Pb-Cu-CB” composite combustion catalyst to enhance plateau effect of this type of propellant.