In this work, we have synthesized Mn-doped SnO2@ZnO nanocomposite for photo degradation of Methylene blue and Rhodamine B dyes upon visible light irradiation. The crystal structure, functional group, optical absorption, defect related emission, morphology, purity and binding energy state of synthesized samples were identified by using various analytical tools. The optical absorption shift and the reduction of band gap values are confirming the formation of hetero-junction of SnO2@ZnO composites. The Mn-SnO2@ZnO hetero-junction effectively induces the photo-generated charge carrier separation and enriches the charge transfer which helps in enhancing the photo-catalytic activities. The photocatalytic degradation results clearly indicate that the Mn-doped SnO2@ZnO nanocomposite has higher degradation efficiency of 98 % and 92 % for the Methylene blue and Rhodamine B dyes, respectively and is higher than the other synthesized samples. The present study reveals a low cost and highly efficient photo-catalyst which works up on visible light irradiation for the purification of waste water from industries.