An electric riding lawn mower including: a seat for a user to ride, a main frame to support the seat, a power output assembly including a mowing element to output power to realize mowing function and a first motor to drive the mowing element, a walking assembly to at least drive the electric riding lawn mower to travel in the direction of a first straight line on the ground and a second motor to drive the walking assembly, a power supply device to power the electric riding lawn mower with a first battery pack, which includes a first battery pack housing and a plurality of battery cells disposed therein. The power supply device is mounted to the main frame. At least one of the first battery packs of the power supply device forms a pluggable connection with the main frame. The battery cells are lithium batteries. The electric riding lawn mower has good adaptability and low usage cost.
