A serial-rotor type high efficiency purification system includes a first rotor, a second rotor and an incinerator. The first rotor has a first adsorption zone and a first desorption zone. The first adsorption zone is adapted to adsorb VOCs and expel a first adsorption-treated air. The first desorption zone is adapted for the VOCs to be desorbed and to expel a first desorption-treated air. The second rotor has a second adsorption zone and a second desorption zone. The second adsorption zone is adapted to adsorb the VOCs within the first adsorption-treated air. The incinerator is adapted to incinerate the VOCs within the first desorption-treated air. The present invention is characterized in that the first adsorption-treated air can be treated again by the second rotor, such that the VOCs concentration of the second adsorption-treated air can be significantly reduced. High processing efficiency can thus be achieved.