Comware

Each time recycling the power on one of the stack edge switches (which is connected directory to the root switch) cause stp root switch to re-calculate stp, which mean a network outages during the re-calculation period. I wonder if there is a way to avoid such issue.

Generally if an edge switch is rebooted it will generate an TC which it is meant to do, but this TC should only cause other switches to flush their mac-address tables. The outage should be very short (if at all).

If it is taking quite some time, make sure you're running the latest firmware versions and ensure your spanning-tree configuration is correct.