Abstract: On the basis of obtained true flow stress-true strain curves of 2519 aluminum alloy at different temperatures and strain rates,the hot extrusion processes of 2519 aluminum alloy tubes were simulated by using DEFORM 2D software.Stress field,strain field,temperature field and variation laws of the extrusion load for this material were obtained at different stages in the extrusion process.The results showe that the relative deviation between the simulated value of extrusion load and the calculated value from empirical formula is about 10%,so simulation result is close to the calculated result.The extrusion velocity must be strictly controlled to prevent overheating structure.