Water locking happens widely in volcanic gas reservoirs. and will seriouly affect the reservoir development. Based on the lab experiments combined with the NMR technology, the damage degree and the damage mechanism under the spontaneous imbibition condition are studied, and the water lock removal process in volcanic gas reservoirs is simulated by the gas flood experiment. It is shown that the water saturation due to the spontaneous imbibition is not linear with respect to the imbibition time, the saturation in the cores is increased dramatically in the first 2h from the time when the imbibition begins, after 16 hours the spontaneous imbibitions are stopped and the saturation remains almost unchanged. Applying the NMR technology to the relation between the water absorption and the pore structure, it is found that the more complex the pore structure, the larger the amount of the water imbibitions will be. The gas is used to draw the water from the cores, and it is discovered that with the increase of the pore volume, the water saturation and the damage rate due to the water locking decrease and they tend to be in moderate levels, the water lock damage is basically avoided after 25 pore volumes are driven by gas. To overcome the drawbacks of the evaluation methodology in water blocking, an improved method, the dynamic evaluation method in water blocking, is proposed.