In order to understand the constant volume combustion performance of single charge and the mixed charge（MC+B） of 37-hole nitroguanidine propellant， a lace-shaped 37-hole triguanidine-15 propellant is used as the main charge （MC）， and the lace-shaped 19-hole triguanidine-15 coated propellant is used as the auxiliary charge（B）. The packing density is 0.20 g·cm^-3， under 50 ℃， 20 ℃， -40 ℃， the effect of arc thickness on the combustion performance of single main charge and the effect of the mixing mass ratios on the combustion performance of the mixed charge （MC+B） were studied through constant volume closed-bomb test. The results show that the lower the temperature， the more obvious the erosion and combustion phenomenon of the 37-hole single main charge. At the same temperature， the greater the arc thickness of the main charge， the less obvious the erosion and combustion phenomenon， the stronger the progressive combustion， and the better the combustion performance. The higher the temperature， the greater the value of ΔL， L_m/L₀ of the mixed charge of the same mixing ratio， the better the progressive combustion； At the same temperature， the progressive combustion of the mixed charge is stronger than that of the single main charge， and as the ratio of the coated propellant increases， the erosion combustion peak gradually decreases， indicating that the addition of the coated propellant significantly improves the progressive combustion and reduces the erosion combustion peak of the mixed charge， and at 50 ℃， 20 ℃， -40 ℃， the mixing ratio of the mixed charge to obtain better progressive combustion is 7∶3.