The orthogonal experiment of thermophilic aerobic fermentation of sick and dead pigs was conducted to optimize the parameters for thermophilic aerobic fermentation of sick and dead pigs.The sick and dead pigs was used as materials，sawdust as additives，and the ratios of additives，fermentation temperature and ventilation rate as factors，and the losses of carbon and nitrogen and the total intensity of odor as indexes.The components of organic malodorous substances in exhaust gas were analyzed and their emission concentrations were determined.The concentrations of ammonia and carbon dioxide were detected as well.The effects of the ratios of additives，fermentation temperature and ventilation rate on the loss of carbon and nitrogen and the emission of odor were analyzed with range and contribution rate analysis.The results showed that 18 organic malodorous substances in total including 3 sulfur compounds，1 alkane compound，12 aromatic hydrocarbon compounds，1 phenolic compound and 1 inorganic compound were detected qualitatively and quantitatively after thermophilic aerobic fermentation for sick and dead pig with sawdust as additives.Among them，p-cresol，methanethiol，dimethyl sulfide，dimethyl disulfide and ammonia were identified as the main source of odor.The factors affecting the loss of carbon and nitrogen were in the decreasing order of additives ratios>ventilation rate>temperature.The factors affecting the total odor intensity were in the decreasing order of temperature> additives ratios> ventilation rate.Considering the loss of carbon and nitrogen and the total intensity of odor comprehensively，the optimized parameters for thermophilic aerobic fermentation of sick and dead pigs are as follows：the additives ratios of 1∶5.5，the fermentation temperature of 55 ℃，and the ventilation rate of 14 L/（L·min）.