A laser energy modulation method based on the coding imaging system was proposed, which allowed the focal plane detector to improve its environmental adaptability with the existence of laser jamming and keep its imaging quality with small fraction loss. A coding imaging system based on the liquid crystal spatial light modulator was constructed and its imaging performance was tested. A laser energy modulation experimental validation system was designed and experiment on the capacity of resisting laser jamming by using coding imaging method under multiple parameters was conducted. The experiment results indicated that the proposed laser energy modulation method based on the coding imaging system can improve the capacity of resisting laser jamming of focal plane detector effectively without significant loss of imaging quality.