Sensor-cloud　is　a　combination　of　wireless　sensor　networks　(WSNs)　and　cloud　computing.　The　emergence　of　sensor-cloud　greatly　enhances　the　computing　power　and　storage　capacity　of　traditional　WSNs　via　exploiting　the　advantages　of　cloud　computing　in　resource　utilization.　However,　there　are　still　many　problems　that　need　to　be　solved　in　sensor-cloud,　such　as　the　limitations　of　WSNs　in　terms　of　communication　and　energy,　the　high　latency　and　privacy　security　issues　due　to　applying　cloud　platform　as　the　data　processing　and　control　center.　The　core　of　edge　computing　is　to　migrate　some　or　all　of　the　computing　tasks　of　the　original　cloud　computing　center　to　the　vicinity　of　the　data　source,　which　gives　edge　computing　great　potential　in　solving　the　shortcomings　of　sensor-cloud.　After　a　lot　of　research,　the　latest　research　status　of　sensor-cloud　was　analyzed,　the　characteristics　of　existing　sensor-cloud　were　summarized,　the　problems　of　existing　sensor-cloud　solution　were　revealed　and　the　implementation　scheme　of　sensor-cloud　based　on　edge　computing　was　proposed.　Finally,　the　challenges　and　future　research　directions　of　the　research　in　sensor-cloud　were　discussed.　©　Copyright　2019,　Institute　of　Software,　the　Chinese　Academy　of　Sciences.　All　rights　reserved.