The solvent-assisted solvent solubilisation method was used for the preparation of maleic rosin ester emulsions, and the optimum process synthesis conditions were determined. The effects of sodium dodecyl sulphate (SDS), alkylphenol polyoxyethylene ether (OP-10) and carboxylated nanofibrillated cellulose (CNF-C) on the particle size and stability of the maleic rosin ester emulsions were comparatively analysed. The process strategy for superhydrophobic paper was constructed using a two-layer coating method, with mechanically pulped nanocellulose and precipitated calcium carbonate PCC as the first coat and maleic rosin ester emulsion as the second coat. It was found that the optimal process conditions for the synthesis of maleic rosin ester were 1:3 ratio of maleic rosin and glycerol; 0.4% dosage of initiator (Azobisisobutyronitrile); 2% dosage of catalyst (nano-ZnO2); and 5 hours reaction at 250 °C. Carboxylated nanocellulose was used as the emulsifier, and the prepared maleic rosin emulsion reached a particle size of 527 nm, which was stable without emulsion breakage and delamination after 90 days of standing at room temperature. The PCC-CNF-MAP-DG coated paper prepared by double-layer coating has a contact angle of 159.1° with water, a cobb value of 2.4 g/m2, and still has super-hydrophobicity after 200 folds, as well as acid- and alkali-resistant, with good chemical stability. The super-hydrophobicity of paper originates from the hold-up of water droplets by air trapped between the two-stage structure, forming a dense hydrophobic layer on the surface of paper fibers.