After local service that saw him bullied into name change, he fled south during the civil war and became a trusted officer to Sun Quan the future Emperor of Eastern Wu during the Three Kingdoms period of China.
A frugal man, he would become a tutor to Princes, diplomat, he rejected military rank and rewards he felt he was undeserving of.
He started his career as an assistant official in the county office before progressing in the early 190's to serve on the staff of Kong Rong, the Chancellor of Beihai State.
After Liu Yao was defeated by the warlord Sun Ce in 195, Shi Yi left him and settled down in Kuaiji Commandery (around present-day Shaoxing, Zhejiang).
Shi Yi agreed and joined Sun Quan's staff, increasingly gaining trust with classified documents and around 211[2] became a Cavalry Commandant (騎都尉).
When Shi Yi protested at appointment due to lack of experience, Sun Quan said, "I may not be a Viscount Jian of Zhao, but does that mean you can't be a Zhou She?
[10] Sun Quan then promoted Shi Yi to Major-General (裨將軍), appointed him as a Palace Attendant (侍中).
When Sun Quan became King, he enoffed his three confidential clerks Hu Zong, Xiang Xu and Shi Yi with the latter made a Marquis of a Chief Village (都亭侯).
[12] In 222,[10] Sun Quan broke ties with Cao Pi and declared independence in his Eastern Wu kingdom.
[b] After the battle, Sun Quan promoted Shi Yi to Lieutenant-General (偏將軍) and recalled him to Wuchang to serve in the imperial secretariat, one of the key organs of the central government, managing court cases and supervising the officials.
Shi Yi remained in Wuchang as an adviser to Sun Deng, who highly respected him and frequently consulted him on policy matters.
[17] Sometime in the 230s, Lü Yi, the supervisor of the audit bureau, falsely accused Diao Jia (刁嘉), the Administrator of Jiangxia Commandery (江夏郡; around present-day Wuhan, Hubei), of defaming the imperial court.
During the interrogation, when Diao Jia's colleagues were asked whether they heard him defame the imperial court, they all said they did, because they feared retaliation from Lü Yi if they said no.
Shi Yi remained unfazed and told Sun Quan, "The sword's blade is now on my neck.
[20] In the same year, Sun Quan sent Shi Yi as an emissary to Shu to extend his condolences and reaffirm the Wu–Shu alliance against Wei.
[c] As Sun Ba's tutor, he gave proper advice to the prince and performed his role in a professional manner.