Portland-sulphur aluminate composite cement slurry has broad application prospect in rapid geological disaster management project, but the rheological properties directly affects the application effect. By combining theoretical analysis with test, the research on the rheological properties of portland-sulphur aluminate composite cement slurry with different mixing proportion was carried out. According to the test results, the curves of shear stress and shear rate of composite cement slurry were drawn; by measuring the time-dependent change of apparent viscosity of the slurry, the time-varying property of cement slurry viscosity was analyzed. The test results show that the water cement ratio has obvious influence on the flow pattern of composite cement slurry; water-reducing agent has no obvious rule to the flow pattern, but has great influence on the rheological parameters of the slurry.