Abstract: Aiming at the auxiliary transfer behavior of rising, standing and excreting in daily life of people with mobility inconvenience, a smart house for the aged and the disabled based on 5 self-developed welfare-robots and sensor network is established. The system provides a service platform for transfer behavior, and a transfer reasoning algorithm and a transfer planning method satisfying safety and comfort requirements are also proposed. Firstly, the function of multiple welfare-robots and the limitation of daily autonomous behavior are discussed. A transfer reasoning algorithm based on reduced rough set is proposed for user groups with different mobility. The corresponding transfer scheme is formulated when user groups are uncertain about their mobility and the patient information is incomplete. Then, rising and standing transfer planning methods are proposed to ensure the safety and comfort of users' behavior. Finally, the transfer method is reasoned and some transfer experiments are completed. Experiments show that the suitable transfer method can be reasoned for users with different mobility by the proposed transfer reasoning algorithm. The plantar pressure of the affected side and the healthy side can be reduced by 39.9% and 19.5% respectively by standing transfer, and the pressure of the back and buttocks can be reduced by 5.05% and 3.95% respectively by rising transfer. The transfer reasoning system based on multiple welfare-robots can be applied to families, nursing homes and rehabilitation centers.