The burgeoning adoption of new energy vehicles has precipitated a surge in advanced vehicular assistant technologies, encompassing systems such as assisted driving and parking. The efficacy of these technologies hinges critically on the selection of suitable image sensors, which are integral to fulfilling the stringent image quality requisites necessary for the implementation of these technologies. Predominantly, these assistant systems are reliant on sophisticated image processing techniques, necessitating high-quality images as a fundamental input for efficacious analysis and recognition. Currently, the Complementary Metal-Oxide-Semiconductor (CMOS) image sensor is predominantly employed in vehicular systems, a choice underpinned by its advantageous attributes such as resistance to interference, cost-effectiveness, and high degree of integration. This paper aims to elucidate the developmental trajectory and fundamental principles of CMOS technology and its application in image sensors. It delves into an analysis of the salient features of CMOS image sensors, especially in their application to parking assistance, autonomous driving support, and fatigue detection systems. Conclusively, the paper offers an exhaustive overview of the current state of CMOS image sensor development, alongside a projection of future trends and an exploration of the challenges that must be surmounted to advance this field further.