A convergent product is a new product that physically integrates the functions of two or more categories into a common product form. Existing literature on convergent products lacks research regarding the degree of functional separation. Therefore, based on the technology acceptance model, the authors explore the impact mechanism of the degree of functional separation on the intention to use. Four studies examine consumers'perceived usefulness and perceived ease-of-use toward convergent products and how these perceptions change with complementarity. The results show that the higher the degree of the product's functional separation, the higher the consumer's perceived usefulness, and the lower the consumer's perceived ease-of-use. Complementarity weakens the effect of functional separation on perceived usefulness, which means for complementary products, the lower the degree of functional separation, the higher the consumer's intention to use. Therefore, enterprises should consider the complementarity while determining the degree of new product's functional separation. This paper fills the gaps in the related fields and has important practical significance for enterprises designing and developing new products.