This　work　introduces　a　new　strategy　of　a　single-atom　nest　catalyst,　whereby　several　single　atoms　are　positioned　closely,　aiming　to　achieve　the　dual　benefits　of　high　atom-utilization　efficiency　while　avoiding　the　steric　hindrance　in　the　coupling　reaction.　As　a　proof　of　concept,　Pt　single-atom　nests,　where　the　adjacent　Pt　single　atoms　are　approximately　4　&　Aring;　apart,　are　precisely　engineered　on　the　TiO2　photocatalyst　for　photocatalytic　non-oxidative　coupling　of　methane.　The　Pt　single-atom　nest　photocatalyst　demonstrates　remarkable　activity,　achieving　a　C2H6　yield　and　turnover　frequency　of　251.6　mu　mol　g(cat)(-1)　h(-1)　and　20　h(-1),　respectively,　representing　a　3.2-fold　improvement　compared　to　the　Pt　single-atom　photocatalyst.　Density　functional　theory　calculations　reveal　that　the　Pt　single-atom　nest　can　significantly　decrease　the　energy　barrier　for　the　activation　of　both　CH4　molecules　in　the　coupling　process.