The fierce market competition environment makes employees feel insecure at work. While it is difficult for enterprises to provide employees with a sense of security, they have to rely on employees' innovative behavior to seek competitive advantage. Therefore, this study focuses on how employees engage in innovative behavior when they face job insecurity. Using a variable-centered approach, this study aims to examine the mediating effects of intrinsic and impression management motivation in the relationship between quantitative and qualitative job insecurity and innovative behavior, including proactive and reactive innovative behavior. In addition, a person-centered approach is used to investigate whether it is possible to distinguish different combinations of quantitative and qualitative job insecurity, and examine the effect of these job insecurity profiles on motivation and innovative behavior. We used 503 data sets collected via the Credamo platform in China into the data analysis. The study found that quantitative job insecurity affects proactive and reactive innovative behavior through impression management motivation and that qualitative job insecurity affects proactive and reactive innovative behavior through intrinsic and impression management motivation. In addition, three job insecurity profiles were identified: balanced high job insecurity, balanced low job insecurity, and a profile dominated by high quantitative job insecurity, all of which have significantly different effects on motivation and innovative behavior. This study contributes to provide new insights into the relationship between job insecurity and innovative behavior and compensate for the limitation of the traditional variable-centered approach that cannot capture heterogeneity within the workforce.