In order to study the burning spectrum of metaldehyde and copper nitrate-ammoniamixture, spectroscopic properties of the mixture were tested by thermogravimetry-differential scanning calorimetry (TG-DDSC) TG/DSC method) and photoelectric detection technology. Based on thermal analysis of the mixture, its thermal decomposition process and possible combustion luminous mechanism were studied, and compared with those tested by the burning spectrum. Results show that the burning flame of metaldehyde is yellow and there is a peak at 591.35 nm which is formed by burning of carbon. When mixed the metaldehyde, thermal decomposition process of copper nitrate-ammonia is changed, with the exothermic peak decreasing from 272.88 ℃ to 254.78 ℃. The green and yellow flame gives off when metaldehyde and copper nitrate-ammonia mixture burns and the spectrum peaks appear separatly at 545.8 nm and 589.33 nm, which is related to carbon burning and forming of copper free radical. The results of theoretical prediction are in agreement with the experimental.