Abstract: A series of filed tests were carried out in 2012 to understand the effects of WoYiDuo (HYT) bio-fertilizer on tobacco growth and development, value, quality and pathogen resistance. The results showed that HYT improved tobacco agronomic traits, yield, quality and enhanced the resistance to diseases. When applied HYT, the tobacco plant height and root fresh weight per plant were increased by 7.47 cm and 61.2 g, respectively, and the yield and output value were enhanced by 222.60 kg/ha and 7937.10 yuan/ha respectively. Moreover, HYT reduced the nicotine content and increased potassium content of tobacco leaves such that the intrinsic chemical composition of flue-cured tobacco became more coordinated. The control efficiency of HYT on tobacco virus diseases, black shank and root-knot nematode disease was 47.13%, 36.06% and 65.62% respectively. Therefore, HYT is a double-effect product both as an insecticide and a fertilizer.