In order to meet the demand of dynamic acquisition in diesel engine, study on dynamic acquisition of cylinder pressure based on digital signal processor (DSP) was conducted. The acquisition method and data process, data communication of dynamic acquisition were proposed, partial acquisition area between 50°CA( crank angle) before top dead center (TDC) and 100°CA after TDC has been presented. Digital signal processor (DSP) and high speed USB (universal serial bus) were introduced into dynamic acquisition, hardware and software for dynamic acquisition system have been designed. The bench test for acquisition performance and stability of this system was finished. Test result showed that dynamic acquisition system of cylinder pressure based on DSP could meet the requirement of diesel engine.