Protein‐inorganic hybrid nanoflowers are new multifunctional materials shown enhanced catalytic performance. Specially, they are used as catalyst and dye decolorizer via Fenton reaction. In this study, the Myoglobin‐Zn (II) assisted hybrid nanoflowers (MbNFs@Zn) were fabricated by using myoglobin and zinc (II) ions in different synthesis conditions. The optimum morphology was characterized SEM, TEM, EDX, XRD, and FT‐IR. The hemisphere and uniform morphology was obtained at pH 6 and 0.1 mg mL−1. The size of MbNFs@Zn are 5–6 μm. The encapsulation yield was ∼95 %. In the presence of H2O2, the peroxidase mimic activity of MbNFs@Zn was spectrophotometrically investigated in the different pH values (4–9). The highest peroxidase mimic activity was found as 3.378 EU/mg at pH 4. MbNFs@Zn was exhibited 0.28 EU/mg after eight cycles. MbNFs@Zn has lost about 92 % of its activity. The usability of MbNFs@Zn for decolorization of azo dyes such as Congo red (CR), and Evans blue (EB) was researched at different times, temperatures and concentrations. The decolorization efficiency was found maximum as 92.3 % and 88.4 % for EB and CR dyes, respectively. MbNFs@Zn has perfect properties such as enhanced catalytic performance, high decolorization efficiency, stability and reusability, and can be excellent potential materials for many industrial applications.