The invention discloses a physical unclonable function circuit comprising n cascaded data delay circuits, n clock delay circuits and an arbitration device; control ends of the data delay circuits are used for receiving random control signals, first output ends and second output ends of the data delay circuits are respectively connected with first input ends and second input ends of the data delay circuits of a next grade, data ends of the n data delay circuits are orderly and respectively connected with input ends of n clock delay circuits, output ends of the clock delay circuits are connected with the arbitration device, and the arbitration device is used for determining output data according to signals output by the n clock delay circuits. Data delay deviation and clock delay deviation can be introduced at the same time via the circuit, mathematical modeling difficulty is increased, and therefore safety of the PUF circuit can be improved.