Komagataella phaffii is a famous host for heterologous protein expression. However, methanol is needed as inducer and lead to toxic and explosive danger when it is used at large amount of industrial scale. Therefore, non-methanol inducer is urgent needed and thus become a hot topic in this research field. In this research, a recombinant Komagataella phaffii expressing xylanase was used to explore non-methanol inducer. The conditions of methanol induction were optimized to obtain 3 403.8 U/mL xylanase, and 97.5 U/mL OD600 specific xylanase. 40.9% intensity of AOX1 promoter under methanol induction was obtained under 0.5% ammounim formate induction. And 2 032.0 U/mL xylanase was obtained at the condition of 0.5% ammonium formate and 0.5% sorbitol addition per 24 h, which was 1.54 fold of AOX1 promoter intensity at the condition of methanol induction. Therefore, ammonium formate combined with sorbitol was an efficient inducer for heterologous protein expression of Komagataella phaffii.