Abstract: The thermogravimetric analysis of the rice husk bio-oil under the air atmosphere was performed. The activation energies for the volatilization, decomposition and char combustion of bio-oil are obtained to be 63.11kJ/mol, 81.01kJ/mol and 161.29kJ/mol, respectively. The experiments for the bio-oil combustion were carried out in a small kiln to focus on the ignition and pollutant emission characteristics. With the modification of the nozzle and the adjustment of the spray velocity, the bio-oil can be ignited successfully by using a pilot flame to preheat the kiln chamber. Bio-oil combustion has the tendency to form CO, which can be effectively reduced with a higher excess air ratio, but the formation of NOx will be increased. By adding methanol or ethanol into bio-oil, the ignition of bio-oil becomes easy, the temperature of combustion is increased, and the formation of CO and NOx is decreased.