A compensation voltage detector is provided. The invention relates to the field of integrated circuits, and aims to solve the technical problem that the existing voltage detector has the disadvantages of limited working voltage, noise disturbance, unstable threshold voltage, output of wrong reset signals, no isolation protection, low generality and the like. The circuit structure comprises a voltage VDD, a step-down regulator and an isolated noise reduction unit which are connected in series, a voltage detection unit of which the input end is connected with the output end of the noise reduction unit, and a voltage compensation unit of which the input end is connected with the output end of the noise reduction unit. The compensation voltage detector of the invention is used to generate a reset signal.