The study focuses on the unsaturated cohesive soil of a high-plateau airport in the southwest mountainous area of China, and the standard penetration tests, laboratory tests, and static cone penetration tests were respectively adopted to carry out a comparative study on the bearing capacity of the foundation soil. The results showed that among the three testing methods, the static cone penetration test method yielded the highest bearing capacity values, The bearing capacity determined by the laboratory test was secondary, and the bearing capacity determined by the standard penetration test method was the minimum. The bearing capacity value determined by the standard penetration test was close to the laboratory test method, and the difference value was not more than 5%. The difference between the static test method and the other two methods was more than 5%. For the studied soil samples, it is suggested that the bearing capacity value should be determined by the standard penetration test method or the laboratory test method, but the static test method is not recommended. The results have some theoretical guidance and practical significance for the analysis of engineering characteristics for the same type of soil.