The polyurethane dispersant was designed into a hyperbranched structure, and a series of UV-curable branched polyurethane dispersants (BPUs) were synthesized by introducing pigment anchoring groups and acrylic groups into the ends of the polyurethane. This structure endowed the dispersant a self-adhesive effect to improve the fastness of printing. The molecular structure and performance of the dispersant were analyzed by infrared spectroscopy, gel chromatography. The pigment paste prepared with BPUs as the dispersant displayed good dispersion performance, uniform particle size distribution and low viscosity. The smallest particle size change within 5 days of high temperature storage was within 20 nm, and the centrifugal stability at 3000 rpm was above 92%. Using this color paste for direct printing, its washing fastness was maintained at 3~4 level, which was about 2 levels higher than commercial dispersants.