This paper selected dredged sand from the lower reaches of the Yangtze River as raw material and prepared four concrete specimens with different dredged sand contents to study the compression-shear performance of the concrete specimens. 1） The paper carried out compression-shear tests under five different axial pressure ratios，and the test results show that the friction coefficient of the compression-shear interface of dredged sand concrete decreases when the dredged sand content is high，while the internal cohesion of the specimens increases as the dredged sand content improves. In addition，the peak value of the compression-shear displacement of the specimens increases first and then decreases as the dredged sand content rises. 2） The paper analyzed the morphology of the damaged interface of the specimens through a scanning electron microscope （SEM） and studied the micro-mechanism of the dredged sand affecting the specimen performance. 3） According to test results and existing literature，the paper proposed a failure criterion based on the octahedral spatial stress and the Ottosen model and presented fitting parameters for the criterion equation. Furthermore，the experimental data are in good agreement with the fitting results.