Water drops extraction of hydrophobic image is an important precondition to evaluate the hydrophobic performance of insulators.The problems associating with initialization and poor boundary catching ability limit the application of Snake model to water drops extraction.A new method based on S-L model is proposed for water drops extraction.The prior knowledge of water drops is used in confirming S-L model’s energy function and the relevant weighting parameters.The water drops extraction based on the S-L model is improved by the adaptive energy item

significantly increasing the extraction precision

and overcoming the shortcomings of the original Snake model.Water drops extraction is improved with the proposed method to provide evidence for further grade evaluation of insulators.