In this study, to improve the cellular interaction and protein release of gelatin hydrogels, we reported the development of a new hybrid hydrogel platform as a promising tissue engineering scaffold and drug delivery carrier. The biodegradable, biocompatible hybrid hydrogel platform was fabricated from gelatin methacrylamide (Gel-MA) and arginine based unsaturated non-peptide polycations (Arg-UPEA) through UV photo-crosslinking, combining the favorable properties of gelatin and arginine. The hydrogels were systematically characterized based on their mechanical properties, swelling mechanics, interior morphology, and biodegradation capability. The in vitro biocompatibility study showed that the hybrid hydrogels show better performance than GelMA hydrogels, in terms of cell attachment and proliferation. Therapeutic proteins were loaded into the hydrogels and their release behavior was investigated. The loading and release profiles indicated that the new cationic gelatin hydrogels could significantly improve the protein loading capabilities, and release the proteins in vitro in a sustained manner. The structure-function study indicated that the material composition has a large effect on the properties of the hydrogels.