This paper illustrates the design and testing of an upper-body exoskeleton for the assistance of individuals with load-lifting and load-carrying tasks, and the provided assistive force can well match with the force required by the human. First, the biomechanics of the human lumbar during the squat lifting of an object is described. Next, the modeling of the exoskeleton is introduced. Additionally, the hardware design of the exoskeleton is presented. The exoskeleton is mainly composed of a back-assist mechanism and an upper extremity labor-saving mechanism, which can assist the wearer’s lumbar during the squat lifting of an object and assist the wearer’s arms to carry an object during walking, respectively. Finally, experiments are conducted to evaluate the performance of the developed upper-body exoskeleton. The experimental results demonstrate that the exoskeleton has the potential to provide assistance for individuals with manual handling tasks. An average assistive force of 44.8 N can be provided for the wearer to lift a 10-kg object. During the squat lifting of the 10-kg object, reductions of 31.86% and 28.30% of the average muscle activities of the wearer’s lumbar erector spinae and thoracic erector spinae are observed, respectively. In addition, a reduction of 23.78% of the average muscle activity of the wearer’s biceps brachii is observed during walking while carrying the 10-kg object.