Dendrolimus　punctatus　Walker　is　one　of　the　most　dangerous　defoliate　insect　pests　which　can　cause　severe　damage　to　the　forest,　so　it　is　of　great　significance　to　find　a　characteristic　index　which　can　identify　the　pest　level　effectively.　Taking　Sanming　City,　Jiangle　County,　Sha　County　and　Yanping　District　in　Nanping　City　in　Fujian　Province　as　the　experimental　areas,　it　constructs　Dendrolimus　pubctatus　Walker　damage　characteristic　index　(DDCI)　from　the　perspectives　of　leaf　area,　uniformity,　greenness,　moisture　and　characteristic　bands　with　selected　indicators　of　leaf　area　index　(LAI),　standard　error　of　LAI　(SEL),　normalized　difference　vegetation　index　(NDVI),　wetness　from　tasseled　cap　transformation,　green　band　B2,　red　band　B3　and　near　infrared　band　B4　on　the　basis　of　principal　component　analysis　(PCA).　This　index　is　coupling　to　the　data　of　ground-space　and　its　total　identification　precision　for　pest　damage　is　79.35%,　the　total　identification　accuracy　is　86.94%　which　indicates　that　it　has　good　ability　of　identification　for　pest　level.　From　the　identification　precision　of　DDCI　in　each　level,　it　is　highest　for　non-damage　level　reaching　95.56%,　after　which　moderate　damage　is　83.33%　and　severe　damage　is　80.00%　while　it　is　lowest　for　mild　damage,　only　reaching　59.57%.　From　the　identification　accuracy,　non-damage　level　is　95.56%,　after　that　severe　damage　is　95.00%　and　moderate　damage　is　91.15%　while　mild　damage　is　71.81%.