The main problems in the current development process of the Internet of Things are outlined

and the feasibility of the combination of software defined network and the Internet of Things is studied. After summarizing and analyzing the relevant software-defined Internet of Things architecture

the SDIoT general architecture is proposed and the basic architecture of Software-Defined Vehicular Networks is discussed. Through the analysis of the existing research results

the challenges and key technologies are elaborated from three aspects: heterogeneous interconnection

resource management

security and reliability. Finally

taking Vehicular Ad-hoc Network as an example

the advantages and prospects of SDIoT applications are clarified

and the possible research directions in the future is prospected.