A water-based pigment jet ink comprises 1-12wt% of a nanopigment, 1-5wt% of a dispersant, 1-15wt% of a modified polyurethane resin emulsion (solid content), 5-25wt% of a humectant, 5-15wt% of an osmotic agent, 0-2wt% of a surfactant, 0-2wt% of a PH adjusting agent, 0.1-0.5wt% of a sterilization antiseptic, and the balance deionized water. The ink has the advantages of excellent preservation stability and printing smoothness, particle nanometer level, complete chromatogram, substantially increased comprehensive properties comprising the light resistance, the water resistance, the chemical resistance, the scratch resistance, high brightness, the high and low temperature resistances, the ageing resistance and the like, and application range enlargement.