The　hollow　mesoporous　SiO2　/dense　SiO2　/Fe3　O4　composite　particles　with　different　pore　sizes　were　prepared　by　a　multistep　coating　technique.TEOS　as　a　silicon　source,and　P123　were　combinated　with　co-surfactant　CTAB　as　template　to　coat　mesoporous　on　the　dense　SiO2　/Fe3　O4　composite　particles.　The　influence　of　the　pore　diameter　in　the　composite　particle　on　the　laccase　immobilization　amount　in　the　composite　particle　and　the　catalytic　efficiency　of　2,4-dichlorophenol　on　hollow　composite　particles　were　researched　in　detail.When　the　pore　diameter　of　the　hollow　composite　particles　was　4.30　nm,the　laccase　immobilization　amount　reached　the　maximum　(234　mg/g).　The　pH　was　within　3　~　8　range,　and　the　activity　of　immobilized　laccase　was　obviously　higher　than　that　of　free　laccase　molecule.　And　the　relative　activity　of　immobilized　lactase　was　highest　when　pH　was　4.　When　the　temperature　was　within　303K　~　353K,the　immobilized　laccase　had　higher　relative　activity　thanfree　laccase　and　the　activity　of　immobilized　laccase　still　remained　28%.　The　removal　rate　of　2,4-dichlorophenol　of　immobilized　laccase　in　the　composite　particles　was　about　80%.　©　2018　Trans　Tech　Publications,　Switzerland.