A riding lawn mower (100) and an operation device (15) thereof. The riding lawn mower (100) comprises a rack (11), a power output assembly (13), a walking assembly (14), a power supply device (16), a control module and an operation device (15). The operation device (15) comprises at least one bracket, an operation lever assembly, a pivot group, and a position detection module. The pivot group is used to pivotably mount an operation lever (151) of the operation lever assembly on the bracket, such that the operation lever (151) can rotate around different axes at different positions in a first direction F1 and/or a second direction F2. The position detection module comprises a magnetic element and a magnetic sensor, the magnetic element is provided on the pivot group or the bracket, the magnetoresistive sensor is provided spaced from the magnetic element so that the magnetic element and the magnetic sensor can generate relative motion for detecting the position of the operation lever (151) in the first direction F1 and/or the second direction F2.
