Gene　therapy　with　small　interfering　RNA　(siRNA)　has　been　proved　to　be　a　promising　technology　to　treat　various　diseases　by　hampering　the　production　of　target　proteins.　However,　developing　a　delivery　system　that　has　high　efficiency　in　transporting　siRNA　without　obvious　side　effects　remains　a　challenge.　Herein,　we　designed　a　new　survivin　siRNA　delivery　system　based　on　polyethyleneimine　functionalized　black　phosphorus　(BP)　nanosheets　which　could　suppress　tumor　growth　by　silencing　survivin　expression.　Combined　with　the　photothermal　properties　of　the　BP　nanosheets,　the　presented　delivery　system　shows　excellent　therapy　efficiency　for　tumors.　Therefore,　the　BP-based　delivery　system　would　be　a　promising　tool　for　future　clinical　applications.