An inlet guide vane assembly of gas turbine is disclosed. The inlet guide vane assembly includes: a plurality of inlet guide vanes, each including a fixing shaft disposed at the end away from a fixing part; and a fixing assembly including a support ring, a fixing ring and an abutting member. The fixing ring includes a fixing wall facing towards a support part, the fixing wall forming, in cooperation with a support wall, a plurality of accommodating cavities corresponding to the plurality of inlet guide vanes. The fixing shafts are rotatably inserted into the accommodating cavities, and the abutting member is in interference fit with the inner inlet casing and the fixing ring. The inlet guide vane assembly implements support for the inlet guide vanes without affecting installation of the inlet guide vanes.