In this work, some combustion experiments on PVC, rice hull, and their mixture were carried out in a fixed-bed reactor to obtain the influence of temperature, oxygen concentrations on the emission of NO. The NO emission during the co-combustion of PVC and rice hull had the same tendency as the rice hull combustion had, and it increased slowly along with the rising of temperature and oxygen concentration. The experiment results also indicate the co-combustion leaded to lower NO concentration, and it was considered that some reducing substances existed in co-combustion process leaded to a certain reduction in NO emission. The FactSage and Chemkin simulation results have a good agreement with the experiment data, and reveal that the main production reactions are: NO2+ONO+O2, NO2+HNO+OH. In addition, large amounts of volatile released by PVC in co-combustion process formed strong reducing atmospheres, which acted the major roles in the NO reduction.