This paper took rape straw as the research object. Based on the TG/DSC-FTIR-MS technology, the dynamic characteristics of combustion were studied systematically with different air flow rates and sample particle sizes. And the qualitative and quantitative characterization analysis of main gas emissions was conducted. The results showed that there was no significant difference on combustion characteristics under different factor-levels. During each burning process, most gas escaped, including a larger amount of CO2 and a smaller amount of alkane gases such as NOx, SO2 and HCl with a diminishing magnitude. Also intensity curves of gases released corresponded to the characteristics of thermal weight loss rate. Quantitative study on the dynamic characteristics of combustion and gas emissions using TG/DSC-FTIR-MS technology could provide basic data and methodological support for the rape straw as environmentally friendly renewable energy.