The utility model discloses a non -contact gyration angle detecting means, the power distribution box comprises a box body, set up the control unit in the box to and communication unit, the control unit locates and is used for the hall sensor who measures cantilever swing drives motor rotating data to be connected at cantilever swing drives motor with communication unit and setting, the communication unit and the PLC of bucket wheel machine communicate, box one side sets up a plurality of cable mouth. The utility model discloses it is more accurate, more reliable to bucket wheel machine angleof revolution measurement to improve the full automatic control's of bucket wheel machine accurate nature.