The invention discloses a grinding wheel balance vibration-absorbing device based on EAP (electroactive polymer) driving and a grinding wheel balance vibration-absorbing method based on EAP driving. The grinding wheel balance vibration-absorbing device based on EAP driving comprises an outer cover and a balance unit, an adjusting screw rod, a positioning slide rod, a driving rod and a counterweight unit. The driving rod controls and adjusts the screw rod to rotate through gear-rack engagement and then adjusts the position of the counterweight unit to achieve linear balance of a grinding wheel,and a first elastic support, a second elastic support, an elastic element, a main mass unit and a damping element are arranged in the counterweight unit to form dynamic vibration absorber effect withdamping. The grinding wheel balance vibration-absorbing device based on EAP driving has the advantages that vibration-absorbing balancing can be achieved timely and properly to avoid the defect thata traditional exterior balance head is untimely in treatment; a signal acquisition process is more precise to reduce exterior vibration interference; movable balance of a rotor is combined with dynamic vibration absorption on the basis of EAP driving, and metal rubber serves as the damping element, so that vibration is reduced and even eliminated, the grinding wheel is more stable to operate, andthe position and parameters of a counterweight are improved to subdue vibration conveniently.