The utility model provides an electrode subassembly and lithium secondary battery who contains it, electrode subassembly contains: contain anodal one or more first electrode, the one or more second electrode that contains the negative pole, and diaphragm, the diaphragm is used for the transition lamination the first electrode with separate between the second electrode and construct in order to have a plurality of folding partial modes, wherein the diaphragm contains: first porous polymer matrix material, formation is in on the surface of first porous polymer matrix material and contain the first coating of polymer adhesive, first coating is in the face of anodal, be in with formation first porous polymer matrix material another on the surface and contain the second coating of the mixture of polymer adhesive and inorganic particulate, the negative pole is faced to the second coating, just constitution, thickness and the porosity of second coating and first porous coating is different. The utility model discloses a security that electrode subassembly can strengthen mechanical properties and finally improve the battery.