  We present a high-efficiency multipartite entanglement purification protocol
(MEPP) for electron-spin systems in a Greenberger-Horne-Zeilinger state based
on their spins and their charges. Our MEPP contains two parts. The first part
is our normal MEPP with which the parties can obtain a high-fidelity N-electron
ensemble directly, similar to the MEPP with controlled-not gates. The second
one is our recycling MEPP with entanglement link from N'-electron subsystems (2
< N' < N). It is interesting to show that the N'-electron subsystems can be
obtained efficiently by measuring the electrons with potential bit-flip errors
from the instances which are useless and are just discarded in all existing
conventional MEPPs. Combining these two parts, our MEPP has the advantage of
the efficiency higher than other MEPPs largely for electron-spin systems.
