Unmanned　aerial　vehicles　(UAVs)are　widely　used　to　provide　network　coverage　in　emergency　situations　due　to　their　high　flexibility　and　air-ground　channel　link.　In　urban　scenarios,　building　blockage　can　severely　weaken　the　link　signal　between　UAV　and　users.　Hence,　how　to　deploy　UAVs　avoiding　link　blockage　as　far　as　possible　is　meaningful　for　improving　UAV　-　user　communication　quality.　To　deal　with　this　problem,　we　propose　two　efficient　algorithms　to　determine　the　optimal　UAV　deployment　in　urban　environment.　Simulation　results　demonstrate　that　the　proposed　algorithms　can　not　only　solve　the　user　comprehensive　coverage　problem,　but　also　obtain　quality　UAV-user　links.