The unconsolidated sandstone gas reservoirs are characterized by shallow burial depth，loose reservoir rock，and complex gas-water distribution，and the formation is prone to the problems of edge and bottom water invasion，particle migration，and mud & sand plugging during the production process，resulting in water and sand production in the wellbore，which affects the normal production of the gas field. In this study，the unconsolidated sandstone gas reservoirs of Sebei Gas Field in Qaidam Basin were selected as the research target to study the main influencing factors of water production，sand production，and formation mud & sand plugging based on the analysis of production engineering factors and the theoretical study of plugging mechanism. The simulation experiments of the mud & sand plugging mechanism under different compaction conditions were carried out，and the plugging mechanism of mud & sand particles and its influence degree on the flow capacity of unconsolidated sandstones were studied by means of mercury injection capillary pressure curve，particle size test analysis，and X-ray diffraction analysis. The results reveal that the main factors influencing sand production in gas wells are production pressure difference，formation pressure，and edge-bottom water invasion. The faster decaying formation pressure and the stronger compaction result in increased formation water when the production pressure difference increases. The permeability of the core decreases rapidly due to the effect of water invasion and compaction when the invasion of edge and bottom water occurs in the reservoirs，and the maximum permeability loss rate reaches 77.40%. The hydration dispersion of the core leads to the smaller size of the mud & sand particles，and the released non-expansive particles such as quartz and feldspar will migrate in the formation. There is a bridge blinding rule of 3df < Dp< 10df between the grain size（Dp）and pore throat diameter（df）of the transported mud and sand particles，which causes mud & sand plugging in the reservoir.When the confining pressure reaches 12 MPa，there is a matching relationship of df >1/3DP between the grain size and pore throat diameter of the transported mud & sand particles，and the mud & sand particles are directly plugged in the pore throat. Therefore，it is not recommended to adopt too high production pressure difference during the production process. For the reservoirs with reduced formation pressures，it is advisable to adopt pressurized development to replenish the energy of the formation.