In order to meet the requirements of fuse’s digital simulation and hard-ware-in-the- loop simulation, a fast algorithm based on the electromagnetic scattering modeling techniques of complex targets in the near field is proposed to calculate the echo power of fuse. The main research work in this paper involves the followings: (1) Considering the influence of antenna pattern and distance as well as spherical wave irradiation, a method established by the PO and PTD and GO methods is presented for electromagnetic scattering modeling of complex targets in the near field. (2) In the filed of EM scattering theory of complex targets for missile-target encounter, the EM scattering model of complex targets is introduced to missile-target encounter model. The relative system of coordinates is established to describe missile-target encounter with parallel track. The system of coordinates of a rocket and the system of coordinates of a target are established to describe polarization and antenna pattern located on the rocket. The system of coordinates of the elementary reflector coordinates is established to calculate EM scattering of the elementary reflector in the near field. The system of coordinates of the target is established to calculate EM scattering after transforming the movement parameter and electromagnetic parameter which are in others system of coordinates into the system of coordinates of the target. (3) A fast algorithm is put forward to calculate the echo power of fuse in the near-field. Numerical results prove its high efficiency and preciseness. The goal of this paper is to calculate EM scattering in any missile- target encounter conditions for fuse’s digital simulation and hard-ware-in-the-loop simulation and the proposed method would be especially valuable in engineering application.