The invention relates to a gripping and releasing tool in the process of switching a thimble plug assembly when a nuclear station reactor core refuels, and particularly relates to a manual gripping apparatus for a thimble plug assembly. Three positioning flanges are fixed on four positioning guide rods at intervals, and positioning pins A are arranged at the tail ends of the positioning guide rods; an upper long guide rod is connected with lower long guide rods, and the two lower long guide rods are connected to the positioning flanges; a position control handle is arranged at the upper part of a guide cylinder A, and the lower end of the guide cylinder A is connected with the upper long guide rod through a guide flange; a hanging ring is connected with a support block, the support block is fixed on an upper pipe, and the upper pipe is arranged inside the guide cylinder A; an upper long rod is connected with a middle long rod, the middle long rod is connected with a lower long rod, the upper end of the upper long rod is connected with a gripping control handle, and the lower end of the lower long rod is connected with a gripper part; guide flanges are arranged at the lower part of the upper pipe, an upper connecting flange is arranged at the tail end of the upper pipe, and a gripping control handle is arranged on the upper pipe; and guide flanges are arranged at the upper part of a lower pipe, and a lower connecting flange is arranged at the top end of the lower pipe.