A mobile power supply for garden tools includes a strap structure and a power supply device. The strap structure includes a waist strap, and a shoulder strap provided on the waist strap. The power supply device is provided on one side of the waist strap. The power supply device includes a power source, a fabric case, and a dummy power source. The power source is provided in the fabric case. This can separate an actual power source from a garden tool, and transfer a large portion of the weight of the garden tool by placing the actual power source on the waist of a user. This uses other parts of the human body to bear the weight of the power source, and reduces the need for user's arm strength. It is easier to operate the garden tools, and therefore can extend the labor time.