Eutectic carbide is a key factor affecting the service performance and service life of Cr8 cold- working die steel. In this paper， aiming at the problem that the carbide non-uniformity in the rolling process of Cr8 steel continuous casting billet exceeds the national standard GB/T 1299—2014 （Level 3）. The rolling model of Cr8 flat steel is established by using Deform finite element simulation software， and the equivalent strain， strain rate and temperature changes in the rolling process are simulated. The morphology characteristics of Cr8 flat steel carbide at different temperature （time） are studied and compared with its continuous casting billet. The results show that the temperature between the center and 1/4 thickness of Cr8 flat steel reaches 1 230 ℃ during rolling， and the carbide is dissolved and precipitated in the triangle grain boundary zone of Cr8 flat steel， resulting in the carbide inhomogeneity level exceeding 3. By reducing the heating temperature and controlling the rolling temperature below 1 200 ℃， the carbide non-uniformity of 24 mm Cr8 flat steel is reduced from grade 4 to grade 2， and the product quality is significantly improved.