The invention discloses a method and optimization for adjusting an XFP optical module which adopts a distributed feedback (DFB) semiconductor laser by the gradual change of a digital potentiometer DAC and making the XFP optical module work at the best working point. The method and the optimization are suitable for a high-speed low-power consumption long-distance transmission optical fiber communication system; a microcontroller adjusts an APC control circuit through lookup tables (LUTs) to compensate bias current Ibias so as to make the set output light power of the DFB laser component the set output light power value which corresponds to the temperature range, and stabilizes the temperature of the DFB laser within the set output light power range through the APC control circuit; and the invention discloses a method for testing through two LUTs and three temperature points, and makes the XFP optical module which adopts the distributed feedback (DFB) semiconductor laser work under the best condition.