A report in the South China Morning Post said Lei Hua had run up a bill of 14,700 yuan (US$2120) in about a year.
It cited a report by a state-owned radio station in Hunan as saying Lei was sacked in October.
The report said Lei started out mining at his home in 2017 after buying his first machine for 10,000 yuan.
When the electricity consumption was noticed, Lei blamed it on air-conditioners and heaters.
Then, in January, the deputy headmaster also started mining at the school, after obtaining a machine with help from Lei.
There was no information on what penalty Lei had attracted.
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