This study aims to reveal the visible-light photocatalytic performance of Pt supported and carbon coated Bi2MoO6 (Pt/C@Bi2MoO6) composite on the degradation of aquatic 2,4-dibromophenol (DBP) pollutant. The surface structure analysis shows that Pt and carbon layer can tightly bind to the surface of Bi2MoO6 with the chemical bonds, and hybrid the original band gap to generate new impurity levels to enhance the visible-light utilization efficiency. The carbon layer has excellent conductivity to transformation electrons from valence band (VB) site, and the supported Pt atoms on carbon layer generate a plasma electron field to enhance the reductive activity on conduction band (CB) site. The Pt/C@Bi2MoO6 composite shows more efficient and reliable abilities in DBP photocatalytic degradation, and the debromination and oxidization processes are performed separately on CB and VB site, respectively. The DBP debromination proceeds by electrons in the CB site in priority to generate non-brominated intermediate products, and then the oxidization and mineralization procedures start by hydroxide radicals in the VB site to finish the complete degradation of DBP. This research reveals the important roles of Pt and carbon layer in band gap structure modification and photocatalytic activity improvement, exhibiting a new insight to design an efficient and stable photocatalyst for persistent organic pollutant degradation under visible-light irradiation.