Abstract: In Chunguang oilfield, the reservoir from Neogene Shawan formation is easy to produce sand due to the unconsolidated sandstone. With the increase of reservoir water content, the sand production is intensified. By continuously tracking the sand production in different time and under different water cut stages, the dynamic reasons of sand production are analyzed. The comprehensive loose index is used to subdivide the cementation types of reservoir rocks, and the mechanism and regularity of sand production in different units of Shawan formation are clarified. At the same time, according to two kinds of micro sand production mechanism of the sandstone reservoir, by taking the reservoir heterogeneity into consideration, the stress model and micro dynamic model of sand production process of Shawan formation are established. It is clear that the main sand production mechanism is like earthworm holes, showing obvious vertical and horizontal heterogeneity, which provides basis for the optimization of sand control process parameters.