In　order　to　meet　various　challenges　in　the　Internet　of　things　(IoT),　such　as　identity　authentication,　privacy　preservation　of　distributed　data　and　network　security,　the　integration　of　blockchain　and　IoT　became　a　new　trend　in　recent　years.　As　the　key　supporting　technology　of　blockchain,　the　consensus　algorithm　is　a　hotspot　of　distributed　system　research.　At　present,　the　research　direction　of　the　consensus　algorithm　is　mainly　focused　on　improving　throughput　and　reducing　delay.　However,　when　blockchain　is　applied　to　IoT　scenario,　the　storage　capacity　of　lightweight　IoT　devices　is　limited,　and　the　normal　operations　of　blockchain　system　cannot　be　guaranteed.　To　solve　this　problem,　an　improved　version　of　Raft　(Imp　Raft)　based　on　Raft　and　the　storage　compression　consensus　(SCC)　algorithm　is　proposed,　where　initialization　process　and　compression　process　are　added　into　the　flow　of　Raft.　Moreover,　the　data　validation　process　aims　to　ensure　that　blockchain　data　cannot　be　tampered　with.　It　is　obtained　from　experiments　and　analysis　that　the　new　proposed　algorithm　can　effectively　reduce　the　size　of　the　blockchain　and　the　storage　burden　of　lightweight　IoT　devices.　©　2020,　Beijing　University　of　Posts　and　Telecommunications.　All　rights　reserved.