AbstractFoam concrete is an excellent new energy‐saving material, but its scope of application is limited due to insufficient foam stability. To improve the foaming performance and applicability of foam concrete, this experiment was conducted with the aim of studying the expansion pattern of foam concrete under different conditions. The experiment mainly studied the extent to which the expansion rate of foam concrete was affected by the dosage of foaming agent (aluminum powder), the substitution rate of double‐quick cement, and the water‐to‐cement ratio. According to the experimental results, when the water‐cement ratio and the substitution rate of rapid‐setting and hardening cement remained constant, the expansion rate of foam concrete initially increased and then decreased as the dosage of aluminum powder increased from 0.05% to 0.4%. Similarly, when the water‐cement ratio and the content of aluminum powder were kept constant, the expansion rate initially increased and then decreased as the substitution rate of rapid‐setting and hardening cement increased from 0% to 100%.