To relieve the fresh water shortage, a skeleton double layer structure (SDLS) is developed in this work to give a high evaporation efficiency for solar steam generation. In the SDLS, the bottom layer is dug hollow to prevent heat dissipating from the bottom layer into the bulk water. The method to optimize structure of the SDLS is also given in this work The increase of height of SDLS has a positive effect on reducing heat losses while negative effect on supplying water, thus a proper height should be selected. After obtaining the proper height, the optimal cross sectional area of the skeleton structure can be approximately calculated based on the mass conservation of water. Applying the optimal SDLS, both of our experiment and simulation methods show that the evaporation rate and the evaporation efficiency under a solar power illumination of 1 sun can be 1.5 kg m(-2) h(-1) and 90% respectively, which is much higher than most emerging structures. The simulation by finite element method further shows that the high evaporation efficiency of the SDLS arrives from the low energy losses. The good match between the simulation and experimental results suggests the reliability of our results. We concluded that the SDLS is a promising system for application in solar steam generation due to its high evaporation efficiency, reusability and also easy to prepare. (C) 2019 Elsevier Ltd. All rights reserved.