The invention discloses a device and a method for measuring service life of a circuit. The device for measuring the service life of the circuit is used for estimating the left service life of a target circuit, and comprises a reference clock receiving end, an associated signal generation circuit, a storage circuit, a measuring circuit and an estimation circuit, wherein the reference clock receiving end is used for receiving a reference clock, the associated signal generation circuit is used for providing an associated signal, at least part of operation conditions of the associated signal generation circuit is synchronized with the operation conditions of the target circuit, the storage circuit is used for storing an initial relationship of the reference clock and the associated signal, the measuring circuit is coupled with the reference clock receiving end and the associated signal generation circuit, and is used for measuring a current relationship of the reference clock and the associated signal, the estimation circuit is coupled with the storage circuit and the measuring circuit, and is used for generating an estimation value according to the initial relationship and the current relationship, and the estimation value is used for indicating the left service life of the target circuit.