Mi Zhu was from Ju county in the Donghai prefecture. His brother is Mi Fang and his sister is Lady Mi.
It is recorded that for many generations, Mi Zhu's clan was prosperous from their business and retained more than ten thousand servants with an enormous amount of wealth numbering to the hundreds of millions. After Liu Bei fled from Yuan Shao to Tao Qian during the battle of Guandu and Tao Qian was on his deathbed, he said that the safety of Xu province rested Liu Bei. Hence, Mi Zhu helped install Liu Bei as the new governor of Xu province.
The Shoushen ji records the famous tale of how Mi Zhu, coming home from Luoyang, passed by a woman asking for a ride. The woman had the transport stopped and thanked Mi Zhu after a distace, revealing she was a heaven-sent messenger whose mission as to burn down the home of Mi Zhu, but due to Mi Zhu's kindness, she warned him then and there. After some discussion with M Zhu, she described that she could not stop heaven's will and would walk slowly to allow Mi Zhu a headstart to make his possessions before the midday fire started. Mi Zhu quickly returned home, took away his possessions, and the home burned.
Mi Zhu was recorded to be poised in manner and highly respected, but did not specialize in political or military affairs, and so was not given command of much.