Light-based 3D bioprinting is an emerging technology to engineer cellular constructs toward functional tissues. However, there is still an urgent need for materials with high printing resolution and allow cell-laden printing. Here, we report a biomacromolecule additive, which can efficiently improve the photocuring resolution of commonly used bioinks, mainly by inhibiting the free radical polymerization at unexposed areas during patterned photoinitiation. Fine structures can be manufactured by digital light processing (DLP) 3D printing and the resolution can reach a 10 μm level. Besides, CSNB can increase the mechanical property of amino-containing materials. CSNB reduces cytotoxicity by avoiding the burst release of photoabsorbers and shows good biocompatibility. GelMA/CSNB bioink was used to print multicell-laden hydrogels with complex patterns and supported the proliferation of encapsulated cells. CSNB thus represents a biocompatible bioink additive that provides an easy approach to improving printing resolution and supports cell-laden printing with multiple cell types.