||Low temperature (<1000℃ ) preheating combustion technique with low NOx emissions has been applied to semi-coke combustion and make a good success. However, the de-NOx potential of higher preheating temperature (>1000℃ ) has not been reported. Aiming to acquire a lower NOx emission, the preheating combustion technique with a higher preheating temperature (>1000℃) has been tested on a two-stage drop-tube furnace in this paper. This work mainly focused on the preheating temperature and the combustion temperature these two factors on the NO emission and burnout characteristic. Results showed that higher preheating temperature (>1000℃ ) could further lower the NO emission and enhance the combustion efficiency due to the early conversion of char-N to N2. The NO reduction percentage can reach as high as 74% as the preheating temperature increased to 1000 °C. Moreover, the NO reduction degree was more significant in the fuel-rich conditions (i.e., α<1 ). Meanwhile, the higher preheating temperature is also conducive to burn out for the early ignition of semi-coke. The effects of combustion temperature on NO emission strongly depend on the stoichiometry parameters. In air-deficient conditions, the NOx emission decreased with increasing temperature, whereas in oxygen-rich conditions the opposite trend occurred. The critical excess air ratio in this paper is around 0.95.