With the rapid development of China's social economy, various industries have made certain progress, among which the development of the construction industry is more prominent. In addition to being affected by the outside world, concrete itself also exists many factors that affect its performance. This experiment is to explore the effect of moisture content on the compressive strength of concrete. The water absorption rate of concrete will seriously affect the mechanical properties of specimens, and the test results show that the compressive strength of the composite with higher water absorption rate is weaker, showing an obvious negative correlation. Considering the relation between the porosity and water absorption of concrete, it is considered that the cavity volume can be characterized by the change curve of water absorption.