Abstract: This paper presents a design of multifunctional portable automated external defibrillator based on STM32F103VC SCM. The defibrillator mainly realizes the defibrillation and ECG analysis function, and according to the clinical actual need, increases information storage and transmission function, query of local records, the function of synchronous LCD display and voice prompt in the defibrillation process. The device uses the defibrillating electrodes to measure body resistance, ECG and so on. We detailedly researched and achieved the discharge module of biphasic defibrillation apparatus based on the damping of two order discharge circuit, and finished the real-time LCD display and voice prompt modules of defibrillation information based on the control of PIC24FJ256DA210 chip.