In order to improve the stability and color fixation of polyurethane acrylate（PUA）resin，firstly，sodium periodate was used to oxidize the hydroxyl groups in sodium alginate molecule to aldehyde groups，and then cinnamamide was grafted through Schiff base reaction to obtain modified sodium alginate（HMSA）， the prepared UV-curable PUA emulsion was used to complete color fixation of pigment printed fabrics. The influence of HMSA on the stability and film forming properties of PUA emulsion was systematically studied，and the fixation effect of the coating on cotton fabric was characterized through tests such as friction fastness，washing fastness，and contact angle. The results showed that HMSA could make PUAemulsion obtain smaller and more uniform droplets，and increase its absolute potential and stability. In addition，HMSA could enhance the acid-base and alcohol-resistant ability of the film. Meanwhile，the UV curable HMSA/PUA system could coat the coating particles on the surface，reduce the probability of their falling off in the process of friction and washing，and thus effectively improve the color fastness.