Hi, I've got my AEO positive this November, and will apply my PR next January, but my postgraduate work permit gonna expire next Apirl, I do need a work permit to extend my legal status.
My question is, am I still eligible to apply LMO even I have AEO in hand already?

You would require a new work permit. You can apply for a LMO even if you have a prior AEO decision (or vice-versa).