Abstract: The control rods are crucial movable components within the pressure vessel of the nuclear reactors, and their insertion depth into the reactor core serves as a key benchmark for assessing the reactivity level of the reactor. During the operation of the reactor, it is essential to conduct the real-time monitoring of the positional information of the control rods. This function should be carried out by the control rod position detectors. The capacitive sensing technology possesses the capability to identify the level information, and shows promising application prospects in monitoring the positional information of the control rods. The method for recognizing the control rod positions based on the principle of capacitive sensitivity has investigated by our research group. Various electrode configurations were designed, including concave electrodes, helical electrodes, and array electrodes. The existing electrode configurations typically employ continuous long electrodes, which can only provide analog signals of the rod position. The advantage of this approach lies in its ability to deliver continuous information regarding the control rod positions. However, a notable shortcoming is that the detector demonstrates inadequate anti-interference capabilities, and its accuracy is easily affected by the tolerances present during the initial installation. To enhance the interference resistance and to mitigate the impact of the installation tolerances to the accuracy of the detector, a method for capturing the digital signals of the positional information of the control rods based on the capacitive sensing technology was proposed in this paper. In order to realize this method, a structural design of the digital type capacitive rod position detector was conducted. As for the digital type capacitive rod position detector, the relationship between the capacitance of the adjacent capacitive elements and the insertion depth of the control rod was analyzed. A method for normalizing the analog signals into the digital signals has designed, and a threshold for determining “0” or “1” digital signals was established. Within the single-phase medium and the double layer mediums, the impact of the axial length of the electrode element and the initial installation tolerance of the detector on the resolution of the detector were analyzed, and the environmental adaptability of the detector under the inclined condition was studied. The research findings indicate that the digital type capacitive rod position detector is capable of accurately identifying the control rod positions under various conditions, including the inclined condition, and situations where the inclination of the detector compounded by the eccentricity of the driving rod.