[Aim]  To investigate the changes in carbohydrate and free amino acid content in the sensitive strain (SS) and pyridaben resistant strain ( Py-R ) of Tetranychus truncatus during different developmental stages, and explore the adaptation mechanism of T. truncatus to short-term high temperature stress, providing a theoretical basis for the comprehensive management of T. truncatus. [Methods]  Eggs, nymphs and female adults were exposed to 34, 38, and 42 ℃for 2, 4, and 6 h, respectively. The content of carbohydrates and free amino acids in the sensitive and pyridaben-resistant T. truncatus strains was measured, and their correlation with high temperature stress analyzed. [Results]  The content of soluble sugar and glycogen in the sensitive and resistant strains of T. truncatus initially increased, then decreased following high temperature treatment, showing a significant difference to the control group (P<0.05). Additionally, the contents of trehalose and free amino acids decreased with an increase in temperature and exposure time. [Conclusion]  The content of carbohydrates and free amino acids in T. truncatus were influenced by high temperature stress. The pyridaben resistant strain had a higher content of stress-resistant substances compared to the sensitive strain, and demonstrated significant high temperature tolerance, enabling it to withstand short-term high temperature stress.