A physical unclonable function PUF device, comprising: at least one processing unit; and at least one PUF unit, a first PUF unit of the at least one PUF unit comprising: a first MOS transistor comprising a first source (S1), first gate (G1) and a first drain (D1); and a second MOS transistor comprising a second source (S2), second gate (G2) and a second drain (D2), wherein the first source and the second source are connected to a same input voltage, the first gate and the second gate are floating, and the first drain and the second drain are connected with a first processing unit of the at least one processing unit, wherein the first processing unit is configured to: output a first random value corresponding to the first PUF unit according to a difference between a first result output by the first drain and a second result output by the second drain, when an absolute value of the input voltage is greater than or equal to a preset voltage. at least one processing unit; and at least one PUF unit, a first PUF unit of the at least one PUF unit comprising: a first MOS transistor comprising a first source (S1), first gate (G1) and a first drain (D1); and a second MOS transistor comprising a second source (S2), second gate (G2) and a second drain (D2), wherein the first source and the second source are connected to a same input voltage, the first gate and the second gate are floating, and the first drain and the second drain are connected with a first processing unit of the at least one processing unit, wherein the first processing unit is configured to: output a first random value corresponding to the first PUF unit according to a difference between a first result output by the first drain and a second result output by the second drain, when an absolute value of the input voltage is greater than or equal to a preset voltage. a first MOS transistor comprising a first source (S1), first gate (G1) and a first drain (D1); and a second MOS transistor comprising a second source (S2), second gate (G2) and a second drain (D2), wherein the first source and the second source are connected to a same input voltage, the first gate and the second gate are floating, and the first drain and the second drain are connected with a first processing unit of the at least one processing unit, wherein the first processing unit is configured to: output a first random value corresponding to the first PUF unit according to a difference between a first result output by the first drain and a second result output by the second drain, when an absolute value of the input voltage is greater than or equal to a preset voltage. wherein the first source and the second source are connected to a same input voltage, the first gate and the second gate are floating, and the first drain and the second drain are connected with a first processing unit of the at least one processing unit, wherein the first processing unit is configured to: output a first random value corresponding to the first PUF unit according to a difference between a first result output by the first drain and a second result output by the second drain, when an absolute value of the input voltage is greater than or equal to a preset voltage. <EOS>