A method for distributing power using multiple power sources is performed by a control device electrically connected to multiple rechargeable power units and a load. The control device creates an output power reference table according to multiple power setting values, output power ranges and battery efficiencies of the multiple rechargeable power units. The output power reference table includes the power setting values and power distribution information corresponding to the power setting values. When receiving a consumed power value of the load, the control device selects corresponding power setting value and power distribution information in the output power reference table and controls the multiple rechargeable power units to simultaneously output power to the load according to the power distribution information. By referring to the output power values of all the rechargeable power units and allocating power outputted from all the rechargeable power units, power utilization efficiency can be enhanced.