The new technological revolution is promoting the intelligent upgrade of vehicles. Traditional vehicles are gradually developing into intelligent connected vehicles (ICVs). New features such as autonomous driving, smart cockpits, and Internet of Vehicle of ICVs have brought users safe, comfortable and interesting travel experiences. Vehicle software, containing a wealth of functions and continuously outputting valuable data, has become the core of the definition of vehicle functions. Traditional vehicle hardware has gradually decoupled from software and become standardized, modular and shared resources. At present, the era of Software-Defined Vehicle (SDV) is coming soon, which is bound to bring subversive changes to both vehicle technologies and industrial ecologies. However, the lack of comprehensive understanding and the clear development way of SDV are ubiquitous in all kinds of corporations in vehicle industry. This will make them be caught off guard when SDV really comes. Therefore, this paper firstly carefully sorted out the key elements and industry development trends of SDV and divided SDV into three development eras. Next, it described the ideal architecture of SDV and identified and analyzed key elements of SDV, which are about the on-board operating system, the control architecture, the role and development trend of hardware and the relationship remodeling among original equipment manufacturers, first grade suppliers as well as information communication and technology companies under the trend of SDV. At last, it predicted the changing trend of vehicle industrial division and give some suggestions for different companies to assist them to make full preparation for the trend of SDV.