High power diode lasers have been used in the fields of pumping source of solid state laser, surface modification, welding, cutting and so on for their high energy conversion efficiency, good reliability, long lifetime and small size. A novel collimator based on double focal lens are proposed, which could collimate the diode laser array in both directions simultaneously, to solve the question of bad collimation effect of diode laser array with high fill factor. Because the parameter design of the SAC and FAC are limited by the compact space of diode laser array with high factor, the double facol lens is the only way to achieve collimation with reducing the installation and adjustment deviation.