The invention discloses a current-voltage converter. The current-voltage converter comprises a buffer circuit, an integral circuit, a comparison circuit, a composite pulse circuit, a pulse amplifying circuit and a filter rectification circuit which are sequentially connected. The current-voltage converter also comprises a multi-section sampling circuit connected between the input end of the integral circuit and the ground, wherein the multi-section sampling circuit receives an externally inputted current signal; the comparison circuit also receives an externally inputted threshold voltage signal; and the composite pulse circuit also receives an externally inputted carrier pulse. The current-voltage converter disclosed by the invention can sample multiple linear sections on a current signal by using the multi-section sampling circuit, and acquires a large isolated voltage signal which is directly proportional to the current signal, and therefore, the linearity of large-scale I/V converters is ensured, the running of the converter is stable, and the errors are reduced.