Abstract: The 1060 aluminum tube/T2 copper rod are selected as the explosive composite rod preparation materials, and the T2 copper tube/Q235 steel tube are selected as the explosive composite pipe preparation materials. Using ANSYS/LS-DYNA software and combining the three algorithms of Lagrangian algorithm, ALE algorithm and SPH-FEM coupling algorithm, the numerical simulation of the explosive welding experiment of preparing two groups of explosive composite pipe and rod at one time is carried out. The simulation results show that the early modeling of Lagrange algorithm is the most concise, followed by the ALE algorithm. In the simulation process, SPH-FEM coupling algorithm takes the most time, and ALE algorithm takes the shortest time. The error between the collision velocity measured by the three algorithms and the theoretical calculation value is 0.9% − 5.3%. The error of SPH-EFM coupling algorithm is the smallest, and the error of Lagrange algorithm is the largest. The principle of energy accumulation inside the tubes is used to explain the diameter expansion of the external composite pipe during the welding process, and the pressure distribution at the composite interface of T2 copper tube/Q235 steel tube is used to verify this phenomenon.