The invention relates to a battery pack dynamic balancer which comprises a battery pack sampling unit which collects necessary information, such as real-time voltage information and temperature information, of a battery pack single body. The collected battery real-time information is transmitted to a micro control unit (MCU) by a data collecting channel. Control strategy information of the MCU is accurately distributed to all dynamic balancing units by control circuits of the dynamic balancing units, and the information is transmitted through an optical isolating coupler. A communication circuit is connected with the MCU and used as a data channel which enables the MCU to exchange information with external devices. Rich battery energy with a higher single body voltage is transferred to an interactive transferring channel of a energy-lacking single body through an energy feeding network. The dynamic balancing units transfer the rich battery energy with the higher single body voltage to the feeding network to achieve that capacities of all the single bodies in the battery pack are balanced. The battery pack dynamic balancer has the advantages of being capable of conducting nondestructive equilibrium on the single bodies in the battery pack and prolonging actual service life of batteries, large in current, high in efficiency and economic benefit, and environment-friendly.