In traditional V-model life cycle for control system development in automotive industry, requirements are specified in documents in the analysis and design phase and will not be verified until they are implemented in software and then tested on a bench or a vehicle. Incompleteness and inconsistence of requirements in documents are difficult to be fannd in the early design stage and often ex- pose in the late production stage, which leads to high cost of rework. This paper demonstrates an effective method of requirements model- ling and verification in the early analysis and design phase using SysML as modelling language and Rhapsody as modelling tool. An exam- ple of a battery contactor control system within 48V hybrid electric vehicle is used to demonstrate this method. With this method, defects of requirements are detected and then refined before the implementation phase. The experimental data tested on vehicles shows that the behaviours of the battery contactor control system meet the requirements defined in the design phase, which proves that this method is ef- fective. The process of requirements modelling and verification is a key part of model based system engineering(MBSE for short)which is regarded as an effective methodology and solution to the development of increasingly complex systems.