Reaction wheels are not only important attitude control actuators for satellites，but also the most prominent onboard micro-vibration source. Considering the varying rotating speed of reaction wheels，this paper proposes a new vibration isolation method using a six-strut isolator combined with the electromagnetic shunt damping （EMSD） technique. A dynamic model of the coupled system consists of a reaction wheel and the isolator is derived including the gyroscopic effect produced by the rotating wheel. The results obtained through analytical analysis and simulations show that gyroscopic effects have a great effect on the natural modes，frequencies，and isolation performance. And then，the influences of key parameters on the isolation performance are analyzed and optimized. Finally，an isolation strut based on the EMSD technique is manufactured and tested. The experiment results verified the influences of the stiffness and EMSD on the transmissibility of the strut.