Gravitational　wave　detection　is　now　more　than　a　mere　verification　of　Einstein＇s　relativity.　It　opens　a　brand-new　window　to　explore　gravitational　wave　astronomy,　therefore　attracts　increasing　attention　of　scientists　from　all　over　the　world.　Focusing　on　space　laser　interferometer　gravitational　wave　detection,　we　give　a　comprehensive　review　on　its　scientific　objectives,　recent　status　and　key　technologies.　With　arm-length　being　of　million　kilometers,　a　space　detector　works　within　a　frequency　band　from　0.1　mHz　to　10　Hz.　Its　possible　sources　include　compact　binary　star　system,　extreme　mass　ratio　inspiral,　intermediate　mass　ratio　inspiral,　super　mass　black　hole　merge,　etc.　The　success　of　space　gravitational　wave　detection　mission　requires　a　pico-meter　precision　laser　interferometer,　and　a　state-of-the-art　drag-free　control　system.　Taking　European　space　gravitational　wave　detector　as　an　example,　we　analyze　space　laser　interferometer　and　drag-free　control　system　in　detail.　The　trend　and　perspective　of　Chinese　space　gravitational　wave　detection　mission　are　also　discussed.