In recent years, a lot of advances have been achieved in research of ternary optical computer. Presently the research of ternary optical computer has entered a new stage in which the focus is on practical application. Reconstruction technique is one of the most important ones of development of the ternary optical computer. Whether the reconstruction can be achieved and how to be implemented determine that whether the ternary optical computer can step into applied fields or not. In this paper, a design of the reconstruction circuit based on Field Programmable Gates Array (FPGA) is proposed, and the implementation of the design is detailed.