The cross-linked modified double base (XLDB) propellants have been prepared by an interstitial-casting technique. The effect of the temperature on the curing quality has been investigated. By observation of the dependence of micro-structure of the propellants on curing time, the possible curing mechanisms of the XLDB propellants has been proposed. The effect of temperature the curing quality of interstitial-casted XLDB propellants has been clarified. A step-curing temperature scheme has been proposed. To provide sufficient time for the smooth completion of the physical curing processes, the curing temperature of the initial stage should be lower than 45 ℃, and the curing temperature of the ending stage should be increase to 60 ℃, so as to accelerate the completion of the chemical curing process. The results show that the curing temperature is the key factor that determines the curing quality and the performances of the interstitial-casted XLDB propellants. Along with temperature rise, the increasing extent of chemical curing rate is higher than the physical curing rate, the performances of these propellants dependent largely on the ratio of the physical to chemical curing. A higher temperature at the initial stage is not preferable for the quality improvement of the propellants.