Based on the principle of the guidance integrated fuzing technology(GIF), an initiation delay time control model for missile and target encounter in three-dimensional space is studied. According to the GIF technology, an estimation algorithm is established for the residual flying time and the initiation delay time based on different data of missile and target encounter. It is shown that the initiation delay time can be expressed as a function of the distance between missile and target R, the angles θ, ø, the anglar accelerations θ, ø when the initiation velocity and the attenuation coefficient of warhead fragments are given.