Three-detector density logging surrounding rock correcting method and device

The invention discloses a three-detector density logging surrounding rock correcting method and device. The three-detector density logging surrounding rock correcting method comprises the steps that the influence laws of surrounding rocks on the density of long, middle and short detectors under the conditions that no mud cake exists and a mud cake exists are analyzed; according to the density values measured by the three detectors of a density logging instrument, surrounding rock correcting formulas under the corresponding conditions are selected to conduct surrounding rock correcting on the three measured density values separately; and the stratum density value measured by the instrument is obtained according to the three corrected density values. According to the three-detector density logging surrounding rock correcting method and device, the influence of the surrounding rocks on stratum density logging under the conditions that the thicknesses of the surrounding rocks are different and whether a mud cake