Abstract: The impact pressure produced by explosive detonation is essential condition of the base plate and cladding plate coalescence for metal explosion welding.Based on Rayleigh-Ritz calculating model and elasticity variation principle, elasticity problem is considered as functional arrest ental equation, and boundary condition of the problem is given. Differential equation and corresponding boundary condition are derived.Instantaneous stress field at impact points was calculated, and analog calculating of different collision angles and impact pressures were carried out.Basic law of stress field distribution at impact points was found.The calculating stress field distribution law can be applied to evaluation and guidance of practical engineering.