<p>Red-bed soft rock is a reddish-toned clastic sedimentary rock, which is widely distributed in southwest China. Quick and effective estimation of its strength can provide technical support for preliminary engineering design or less critical structure design in red-bed soft rock areas. Due to the low strength and easy disintegration and fragmentation of the red-bed soft rocks in southwest China, it’s difficult to prepare and transport standard cores in the field. In order to quickly obtain the strength index of red-bed soft rocks in southwest China, a series of laboratory index tests (Uniaxial Compression tests (UCT); Point Load tests (PLT); ultrasonic pulse velocity test (UPV); Schmidt rebound hammer test (SHR)) were performed. Regression analysis was conducted for each index to establish its corresponding prediction model. Validity analysis and a comparative study of the prediction models were carried out to assess the potential relevance of the strength properties of red-bed soft rocks and the accuracy of the prediction models. The results of the study show that within the 95% prediction interval and confidence interval, there exists a strong correlation among various indicators of the red-bed soft rocks in Southwest China. The model comparison study proved that the rock empirical UCS (Uniaxial compressive strength) formulas exhibit strong regionalism in practical application, and there are large errors in predicting UCS of red-bed soft rock in China using improper prediction formulas. The UCS and SHR prediction models for red-bed soft rocks in Southwest China proposed in this study have good prediction performance.</p>