This thesis is to design a Positive/Negative pulse battery charger with a high positive pulse current to charge battery quickly , The negative impulsive discharge current is used to accelerate chemical reaction between pole plates be response. Finally, there is a rest time to let charging effect uniform and to reduce temperature so as to last battery life cycle. The thesis uses dsp to control the single-stage Flyback converter charging battery then combine flyback DCM model and voltage follower control to increase efficiency. The chemical reaction of the negative pulse discharging mode. CMOS switch series connection resistance would speed up . Finally we join two-stage positive/negative pulse battery deep discharging to strengthen the lithium battery chemical reaction and efficient reduce the charging time ,it causes the fixed current charge able to enter more electric quantities until achieving 4.2v lithium battery's definition voltage sufficiently then transforms into the fixed voltage charge. this circuit has reached the goal of high-power Factor and quickly charging to extend life cycle of battery In order to understand the influence of positive/negative pulse ,we measure voltage, temperature and time period of charging and discharging in the experiment.