The invention relates to a nano film-embedded emulsion lubricant and mainly solves the problems about high frictional resistance of a horizontal well, serious backing pressure and poor lubricating effect of drilling fluid. The nano film-embedded emulsion lubricant comprises the following components in percentage by weight: 10 to 30 percent of modified paraffin, 3 to 11 percent of a compound emulsifier, 0.5 to 3 percent of an alkalinity modifier, 0.5 to 2 percent of nano graphite powder and the balance of water. The nano film-embedded emulsion lubricant provides an emulsion lubricant which has low fluorescence, is provided with a nano ball material and has capability of forming an anti-adhesion lubricating film between the stratum and a drilling tool; a prepared drilling fluid system has a good lubricating property; a mud cake is fine; the filter loss is low; the class of florescence is low; the nano film-embedded emulsion lubricant has excellent thermal stability and cold-resisting stability; drilling efficiency of the horizontal well is greatly improved.