A power supply apparatus configured to supply power to a data center, the data center comprising a first device and at least one second device (951, 952); the power supply apparatus comprises a first uninterruptible power supply UPS, a second UPS and a control apparatus, the first UPS is configured to control a first power source and a first energy storage apparatus to supply power to the first device, and the second UPS is configured to control the first power source and a second energy storage apparatus to supply power to the at least one second device(951, 952); importance of a service in the first device is higher than importance of a service in each second device(951, 952), and the service in each second device(951, 952) is transferable; wherein the sum of the power that is input by the first power source to the first UPS and the power that is input by the first power source to the second UPS is a fixed value; the control apparatus is configured to: limit the power input by the first power source to the first UPS to a rated value, the power that is input by the first power source to the second UPS is the power of the first power source minus the rated value of the first UPS; or when a quantity of electricity of the first energy storage apparatus is less than or equal to the first preset quantity of electricity, limit input power that is input by the first power source to the second UPS to the power of the first power source minus the power that is input by the first power source to the first UPS, wherein the power that is input by the first power source to the first UPS is determined based on the power requirement of the first device; wherein the processor is further configured to: when a quantity of electricity of the second energy storage apparatus is less than a third preset quantity of electricity, send transfer indication information to at least one target second device in the at least one second device, wherein the transfer indication information is used to indicate the at least one target second device to transfer a service. the power supply apparatus comprises a first uninterruptible power supply UPS, a second UPS and a control apparatus, the first UPS is configured to control a first power source and a first energy storage apparatus to supply power to the first device, and the second UPS is configured to control the first power source and a second energy storage apparatus to supply power to the at least one second device(951, 952); importance of a service in the first device is higher than importance of a service in each second device(951, 952), and the service in each second device(951, 952) is transferable; wherein the sum of the power that is input by the first power source to the first UPS and the power that is input by the first power source to the second UPS is a fixed value; the control apparatus is configured to: limit the power input by the first power source to the first UPS to a rated value, the power that is input by the first power source to the second UPS is the power of the first power source minus the rated value of the first UPS; or when a quantity of electricity of the first energy storage apparatus is less than or equal to the first preset quantity of electricity, limit input power that is input by the first power source to the second UPS to the power of the first power source minus the power that is input by the first power source to the first UPS, wherein the power that is input by the first power source to the first UPS is determined based on the power requirement of the first device; wherein the processor is further configured to: when a quantity of electricity of the second energy storage apparatus is less than a third preset quantity of electricity, send transfer indication information to at least one target second device in the at least one second device, wherein the transfer indication information is used to indicate the at least one target second device to transfer a service. limit the power input by the first power source to the first UPS to a rated value, the power that is input by the first power source to the second UPS is the power of the first power source minus the rated value of the first UPS; or when a quantity of electricity of the first energy storage apparatus is less than or equal to the first preset quantity of electricity, limit input power that is input by the first power source to the second UPS to the power of the first power source minus the power that is input by the first power source to the first UPS, wherein the power that is input by the first power source to the first UPS is determined based on the power requirement of the first device; wherein the processor is further configured to: when a quantity of electricity of the second energy storage apparatus is less than a third preset quantity of electricity, send transfer indication information to at least one target second device in the at least one second device, wherein the transfer indication information is used to indicate the at least one target second device to transfer a service.