Fluorescence Optical Diffusion Tomography (FODT) is considered as one of the most promising ways for non-invasive molecular-based Imaging. Many reconstructed approaches to FODT utilize iterative methods for data inversion. However, they are regarded as being time-consuming and far from meeting the real-time imaging requests. In this work, a fast pre-iteration algorithm based on the generalized inverse is established, which divides the image reconstruction into two steps that are off-line pre-iteration and on-line one-step reconstruction. In the pre-iteration step for obtaining the approximation of generalized inverse, a second order iterative format is employed to accelerate the convergence. Simulation based on the linear diffusion model shows that the distribution of fluorescent yield can be well estimated by this algorithm with second-order iteration. And the reconstructed speed is remarkably increased. Time-efficiency of this method will potentially promote the development of real-time imaging and the dynamic monitoring of molecular activity.