Display omitted •Wood lignin derived carbon quantum dots for in-situ photothermal thermogenesis.•Green fabrication strategy of wood resources with ecological and economic merits.•Evaporation performance of 1.18 kg·m−2 with efficiency up to 79.5% was achieved.•Fast induced thermogenesis performance and water adsorption via capillary force.•Water transportation and evaporation mechanisms were comprehensively revealed. Photothermal evaporation and desalination via renewable solar energy has promising potential to alleviate freshwater scarcity. However, recent reported systems usually lack sufficient environmental compatibility, ecological security, and energy-saving concern. Here, a novel and green photothermal evaporation system with ecological and economic advantages was designed. An evaporation performance of 1.18 kg·m−2 (1.09 kg·m−2·h−1) with up to 79.5% efficiency at one sun illumination (1 kW·m−2) was achieved. More importantly, a series of simulation and numerical modelling was synchronously developed to analyze in-depth the main factors that affect water transportation and evaporation processes. The channel size, temperature distribution, and formed gradient were carefully investigated and discussed. Notably, this system exhibited satisfactory repeatability and stability. In addition, only a few photothermal components are required in this system, which will also bring a significant economic merit. Taken together, this work successfully provides new insights into developing a sustainable photothermal evaporation system with ecologically friendly property and satisfactory performance in practical application. Moreover, it also reveals the corresponding water transportation and photothermal evaporation mechanisms, and maximizes the evaporation efficiency.