The utility model provides a well depth surveying device, which comprises an optical pulse generating device, a counting circuit and a calibrating circuit. The calibrating circuit is connected with the counting circuit, and is used for receiving optical pulses from the optical pulse generating device, adjusting the number of the optical pulses according to a control instruction to form count pulses, and outputting the count pulses to the counting circuit for counting. According to the well depth surveying device, the accuracy of the well depth survey is improved through the calibration of the calibrating circuit; meanwhile, the service life of a driving wheel and a cable is prolonged and resource consumption is reduced.