Abstract: In order to ensure the fast regulation response capability of the reactor power, Qin No.2 Plant uses control rods to ensure the rapid regulation of power. During power operation, if there is an abnormality in the reactor power regulation system and the control rods are uncontrollably inserted, it will cause disturbances to multiple important parameters such as the average temperature of the primary circuit, regulator pressure, regulator water level, steam generator water level, and turbine power. If intervention is not timely, the unit may experience major transients such as shutdown and safety injection system startup, which have a significant impact on the safety of the unit. This article will analyze the risk of uncontrollable insertion of the reactor control rods during power operation, explain the causes, and develop corresponding countermeasures to ensure the safe and stable operation of the unit.