The　photovoltaic　curtain　wall　is　a　combination　of　an　outer　photovoltaic　module　plate　and　inner　vacuum　glass,　which　forms　a　narrow　cavity　with　obstacles　such　as　beams　and　junction　boxes　inside.　After　the　cavity　of　the　photovoltaic　curtain　wall　is　contaminated,　it　is　impossible　to　enter　manually.　For　the　problem　of　cavity　cleaning,　a　cross-frame　barrier-crossing　and　wall-climbing　cleaning　robot　is　developed.　The　robot　body　mechanism　is　designed　as　a　cross-frame　motion　mechanism　to　achieve　flexible　movement　in　narrow　cavities;　its　adsorption　device　is　designed　as　a　liftable　3∗5　vacuum　suction　cup　set　to　achieve　stable　adsorption　on　the　vacuum　glass　surface　and　the　function　of　crossing　obstacles;　its　cleaning　structure　is　designed　as　a　foldable　brush　cleaning　structure　to　achieve　the　cleaning　function　on　the　photovoltaic　module　surface.　Based　on　the　kinematic　model,　the　robot　motion　simulation　analysis　was　completed;　the　robot　prototype　was　developed,　and　the　adsorption　and　movement　experiments　of　the　robot　were　carried　out.　The　experimental　results　show　that　the　robot　can　achieve　stable　adsorption　and　autonomous　movement　on　the　vertical　wall　surface.　©　2023　IEEE.