Trehalose, as a non-reductive disaccharide, plays a vital role in plant growth and development and resistance to abiotic stress. Trehalose-6-phosphate synthase (TPS) is a key enzyme in the synthesis mechanism of trehalose and TPS1 genes play a crucial role in the response to abiotic stress in plants. However, it has rarely been reported that CaTPS1 responds to cold and salt stresses in pepper. To verify the function of CaTPS1 in response to cold and salt stresses, CaTPS1 was silenced by virus-induced gene silencing (VIGS). Subsequently, the expressions of CaTPS1, plant morphology and some physiological indexes were analyzed after cold and salt stresses in pepper. The results showed that the expression of CaTPS1 was significantly lower in CaTPS1-silenced (pTRV2-CaTPS1) plant than that in the non-VIGS (CK) and negative control (PTRV2-00) plants. The parameters of response to cold and salt stresses have changed accordingly. The chlorophyll content decreased, while the trehalose content, peroxidase (POD) activity, catalase (CAT) activity and ascorbate peroxidase (APX) activity increased in all treatments. However, these parameters of response to cold and salt stresses were significantly lower in pTRV2-CaTPS1 plant than in CK and PTRV2-00 plants. This study suggested that CaTPS1 was involved in the response to cold and salt stresses in pepper.