During the technology adjustment process of automatic production line for half shaft bushing with multi-station hot extrusion, punching slug adhesion defect appeared in the tube end during the forward extrusion process. The possible causes of slug adhesion were explored. Through a comprehensive analysis of process flow and on-site conditions, it was proposed that the uneven circumferential heating temperature of cylindrical billet was the key influencing factor. Finite element analysis software Deform was used to simulate the deformation and shearing process of materials in backward extrusion and slug punching under different heating temperature conditions. Through the analysis of simulation results, the mechanism of slug adhesion was revealed, and it was concluded that the slug could be washed down smoothly when the circumferential heating temperature difference of billet was less than 30 ℃.According to the reasonable temperature difference obtained by the simulation, the field test shows that the actual situation is consistent with the simulation result. The incisions of product forging were even, and the slug tearing zone is evenly distributed, which effectively solves the problem of slug adhesion.