Abstract Buoyancy is a key concept in secondary school physics, but students encounter many difficulties in this content, among which ‘whether the object on the soil receive buoyancy’ is an important question. In order to solve this problem, we designed and carried out an experiment to suss out how soil impacts an object’s buoyancy. We did this by gauging the actual buoyancy versus the theoretical buoyancy of the object through two separate methods, and then we dug into the discrepancies between those two readings. The following conclusions were obtained: Objects on soil experience buoyancy, which varies with different types of soil. After demonstrating this experiment in teaching practice, the majority of students were able to gain a better understanding of buoyancy in daily life. This indicates that the experiment has a significant promotional effect on middle school students’ learning of the buoyancy chapter and using it to recognize buoyancy in daily life, and it can be used as one of the supplementary inquiry experiments in the education of middle school buoyancy courses.