With　the　intensification　of　energy　crisis　and　environmental　pollution,　solar　photovoltaic　technology　has　been　paid　more　and　more　attention　by　many　countries.　However,　dust　on　the　surface　of　the　photovoltaic　panels　is　one　of　the　main　factors　affecting　solar　photovoltaic　(PV).　In　this　paper,　multiple　factors　(precipitation,　wind　speed,　wind　direction　and　inclination　angle)　were　considered　to　analyze　the　effect　of　dust　on　the　PV　panels　by　weighing　and　transmittance　determination　in　Tianjin,　China.　A　test　platform　with　4　typical　orientation　and　7　inclination　was　built　to　measure　the　transmission　of　PV　panels　in　the　outdoor.　The　results　showed　that　the　southward　PV　panels　were　affected　by　wind　velocity　and　direction　more　than　others.　Dust　on　southward　PV　panels　increased　rapidly　at　first,　and　then　decreased　under　the　influence　of　rainfall.　Without　rainfall,　the　dust　on　southward　PV　panels　placed　in　45°　for　30　days　was　1.90%　lower　than　that　in　the　eastward,　and　7.32%　and　11.95%　higher　than　those　in　the　westward　and　northward,　respectively.　The　functional　relationship　between　dust　density　and　dip　angle　was　established　by　regression　analysis,　and　the　best　cleaning　time　of　PV　panels　is　once　a　month　except　in　rainy　season.　©　2022　Elsevier　Ltd