The removal of organophosphorus pesticides residues from wastewater of fruits and vegetables processing as well as other agricultural processes by a low-cost, environment-friendly, and efficient strategy is necessary. In this study, rice bran protein (RBP) was cross-linked with ceric ammonium nitrate (CAN). The results showed that the cross-linking process generated new functional groups and significantly enhanced the chemical reactivity and adsorption capacity of RBP. The RBPC showed rough and porous surface structure compared with smooth surface structure for RBP. In addition, greatest adsorption capacity of 193.0 mg/g and omethoate removal efficiency of 72.1% was achieved, and the results fitted well with Langmuir isotherm and pseudo-second order models. Moreover, Omethoate (5 mg/L) removal efficiency maintained over 60% after 5 cycles of RBPC usage. Therefore, the obtained RBPC complex can be suggested as an efficient adsorbent for the removal of pesticide residues from wastewater.