[Purposes] The variation law of unsaturated shear strength with water content and compaction degree was analyzed in sandy soil of weathered granite gneiss. [Methods] Taking the typical weathered granite gneiss sandy soil filler from the western Dabie Mountains in Anhui as the research object, non-saturated samples of this sandy soil in 20 different combinations of water content and compaction degree were prepared using the static pressure molding method. The influence of current water content and compaction degree on its shear strength parameters was analyzed through large-scale indoor direct shear tests. The corresponding comprehensive correlation models were established by regression, and their prediction accuracy was verified. [Findings] Under the same compaction degree, the cohesion and the internal friction angle of soil samples have significant unimodal left-skewed Gaussian function correlation and a power function negative correlation with the water content ratio (ratio of water content to optimum water content), respectively. Under the same water content, both of the cohesion and the internal friction angle have significant logarithmic function positive correlation with the compaction degree. The established comprehensive correlation models of cohesion as well as internal friction angle with water content and compaction degree are higher in prediction accuracy. [Conclusions] The prediction models can be used to predict the pseudo-cohesion strength characteristics for the compacted sandy soil, providing reference for the strength parameter modeling of similar soil.