The rotate vector (RV) reducer often experiences failure due to excessive wear of the needle roller bearings (NRBs) during operation. To investigate the dynamic wear characteristics of the NRBs in RV reducers, a contact multibody dynamics approach is employed to obtain the forces and motion conditions of the NRBs, along with calculations of heat flux and convective heat transfer coefficient (CHTC). The steady-state temperature of NRBs within the RV reducer is numerically investigated through finite element analysis (FEA). A dynamic contact force model of the RV reducer's NRBs incorporates coupled thermo-mechanical effects at the temperature, enabling accurate prediction of bearing contact forces under thermal deformation. Archard's wear model incorporates thermal deformation effects to enable accurate wear prediction in RV reducer NRBs under thermo-mechanical operating conditions to validate the accuracy of this method, a long-term fatigue wear test is conducted on the RV reducer. After the reducer has been operated for an extended period and is disassembled, the wear depth distribution of the inner and outer raceways of the NRBs is inspected, thereby confirming the validity of the proposed method.