Tight sandstone gas reservoirs have a great potential of resource, which can make up the conventional natural gas. Although the accumulation process and gas—water distribution of tight sandstone gas is so important to the success of gas exploration, the study on them are insufficient. In order to cope with the above scientific challenges, after adequately reviewing and comprehending previous research findings, a serial of 2D physical experiments have been done to simulate the accumulation process and gas—water distribution of tight sandstone gas. The result of the experiment showed that the accumulation process of tight sandstone gas can be divided into three stages; they are the precharging stage of energy accumulation, the charging stage of gas episodecharging and the postcharging stage of natural gas conservation. The stage of gas episodecharging is the key for tight sandstone gas reservoirs. And the complexity of gas—water distribution is contributed to the heterogeneous reservoir.