For the purpose of utilizing decomposition component analysis (DCA) for fault diagnosis of SF 6 gas insulated equipment further, SF 6 spark decomposition experiments under different spark energies were carried out on the frequency and energy-controllable SF 6 spark decomposition test platform. The amount of gaseous by-products of SF 6 sparks were measured by GC-MS. Atomic relative content of solid products were analyzed by XPS. The main gaseous by-products of SF 6 sparks include SOF 2 , SO 2 F 2 , SOF 4 , SO 2 , as well as CF 4 , and the amount of them increases with spark number. The amount of SOF 2 increases with single spark energy and tend to be saturated, while SO 2 F 2 decreases. It depends strongly on the differences of both the energies consumed in SF 6 dissociation process into SF 5 , SF 4 , SF 2 , and hydrolysis rates of SOF 4 and SF 4 . Besides, CF 4 increases with single spark energy and tend to be saturated, and SOF 4 shows a linear dependence, but SO 2 is hardly influenced by spark energy distinctly. In solid products, relative content of F, S, Fe, W increases with spark energy. The main existence forms of Fe include FeS, FeF 3 , Fe 2 O 3 , and pure Fe, thereunto the relative content of FeS and pure Fe increases with spark energy.