In order to focus coherent light and image through scattering media in noisy environment, a score assessment algorithm is proposed to optimize the phase distribution of the incident wavefront. The basic idea of the score assessment algorithm is to mark the phase value according to the target intensity in the optimization process. Binary phase optimization is exploited to increase the speed of the program, which can be applied to dynamic scattering media. Compared with the ant colony algorithm, it is found that the score assessment algorithm can achieve a focus under strong disturbance, while the ant colony algorithm is invalid in noisy environment. In experiments, it is found that the intensity of the target signal is enhanced 71.4 times over the average speckle intensity using the score assessment algorithm. Therefore, the score assessment algorithm should be considered firstly in the application of biological imaging, photoelectric detection and other fields.