Traditionally,　the　accuracy　of　range　queries　in　differentially　private　histogram　publication　was　boosted　by　obtaining　the　Best　Linear　Unbiased　Estimator　(BLUE)　of　the　nodes＇　noisy　values　in　the　Differential　Privacy　Range　Tree　(DPRT).　However,　exist　works　require　DPRT　be　perfect　k-ary,　which　means　it　is　not　suitable　for　differentially　private　histogram　publication　under　arbitrary　tree　structure　In　this　paper,　we　propose　an　efficient　iterative　algorithm　GBLUE　for　differential　privacy　histogram　publication　based　on　any　tree　structure.　The　correctness　of　GBLUE　is　guaranteed　by　theoretical　analysis　and　experimental　demonstration.　Experimental　results　show　that　GBLUE　is　effective　and　feasible.