Abstract: The mechanical properties and microstructure segregation of continuous casting billet and hot rolled strip of high carbon steel were tested. The results show that there is carbon segregation on the inner arc side of continuous casting billet, and local segregation spot exists in hot rolled strip, and network cementite exists, so brittle fracture is easy to occur in hot rolled strip. By optimizing the casting speed, specific water quantity and the reduction of tension levelers, the carbon segregation of the continuously casted billets is lowered from 1.10 to 1.04, and the segregation spot and network cenmentite of hot-rolled wire rods are eliminated, and the qualified rate of mechanical properties is increased from 62.3%to 99.3%.