棒位系统用于实时监测和显示控制棒在反应堆内的位置，棒位测量是反应堆安全运行的重要保证，若控制棒有超过25%测量棒位出现异常，将导致反应堆由功率运行状态后撤到热停堆状态，影响机组经济效益.针对福清核电3、4号机组国产棒位系统调试及运行期间导致测量棒位显示异常问题，结合卡件的工作原理，使用Multisim软件模拟仿真分析问题产生的原因，并制定相应的改进措施；经过测试和验证有效解决了测量棒位显示异常问题，提高了卡件工作的可靠性，保障了反应堆的稳定运行.

The rod position system is used to monitor and display the position of the control rod in the reactor in real time. The rod position measurement is an important guarantee for the safe operation of the reactor. The rod position system is not used to generate protection or control signals. If the rod position is abnormal in more than 25% of the measured rod positions, the reactor will cause the reactor to withdraw from the power operation state to the hot shutdown state, which will affect the economic benefits of the unit. Aiming at the problems of measuring rod position display caused by the debugging and operation of domestic rod position system of unit 3 and 4 of Fuqing nuclear power plant, combining with the working principle of the card, Multisim software is used to simulate and analyze the causes of the problems, and corresponding improvement measures are formulated. Through the test and verification, the abnormal situations of measuring rod position display are effectively solved, the reliability of the card work is improved, and the stable operation of the reactor is guaranteed.