The accused Wang Yan-Ming, 46, operated a tuition centre in Taizhung.
It was reported that he would often take advantage of his female students while playing videos in an underground room.
He told his victims not to report to their parents as he would be “sentenced to death”.
In 2010, a 11-year-old rape victim told her mother she felt pain in her private parts.
The girl told her what had happened and Wang was arrested.