The increasing adoption of cutting-edge technologies, such as cloud computing and machine learning by robots that replace human workers, has posed serious challenges to employees’ career sustainability (CS), affecting their innovative work behavior (IWB). As the digitalization of the workplace continues to progress as normal, further investigations into the relationship between CS and IWB are urgently required. In response, we investigate the relationships among CS, IWB, human capital (HC), and user resistance (UR). Using data collected from 537 employees in Chinese high-tech enterprises, structural equation and regression analyses were performed. Our results reveal that (1) three dimensions of CS (career renewability, career flexibility, and career integrity) are positively related to IWB, while the fourth dimension of CS (career resourcefulness) exerts inverted U-shaped influences on IWB, and (2) there is a significant dual moderating effect between UR and HC on the four dimensions of CS and IWB, with the former demonstrating a negative effect and the latter showing a positive effect. These findings offer valuable insights for global managers and policymakers to more appropriately implement HR practices in this highly competitive international market. Adopting a conservation of resources theory (COR) framework and the Job Demands–Resources model (JD-R), we theoretically elucidate how different dimensions of CS serve as personal resources for IWB in the digitalized context, thereby enriching the literature on innovative behavior and career development.