Abstract: Lightweight soil is a novel technological material that boasts characteristics such as low density, high strength, thermal insulation, vibration isolation, environmental friendliness, and cost-effectiveness. These features make it highly suitable for a wide range of applications in geotechnical engineering, including roadbed backfill, soft foundation treatment, and tunnel load reduction. The influence of vibration loads resulting from transportation, earthquakes, waves, and other factors on the mechanical properties of lightweight soil has garnered considerable attention in recent research. This paper expounds on the influence of factors on the dynamic deformation characteristics and dynamic strength properties of lightweight soil. These factors include the mix ratio (such as the content of lightweight materials, dosage of curing agent, and moisture content), stress state, vibration frequency, dry–wet alternation effect, and freeze–thaw cycle. Additionally, we summarise the calculation model for the dynamic shear modulus and damping ratio of lightweight soil. The findings reveal that the incorporation of curing agents, such as cement and fly ash, substantially improves the resistance of lightweight soil to dynamic loads. Additionally, the distinctive pore structure of lightweight soil markedly enhances its vibration isolation effect. As dynamic strain increases, there is a nonlinear decrease in the dynamic modulus of lightweight soil while the damping ratio increases nonlinearly. Adjusting the content of lightweight materials and the dosage of curing agents can markedly improve the seismic reduction effect of lightweight soil, thus granting it greater dynamic stability. The coupling effects of dry–wet cycles, freeze–thaw cycles, and dynamic loads may lead to a degradation in the dynamic performance of lightweight soil. To extend its service life in practical engineering applications, the implementation of a waterproof layer is recommended. Model tests and numerical simulations substantiated the commendable dynamic stability and durability of lightweight soil in real-world engineering scenarios. Finally, following a comprehensive literature review, this paper identifies potential research directions. The study of dynamic characteristics in lightweight soil is still in its infancy, with the dynamic properties of novel solid waste lightweight soil remaining largely unexplored. Further exploration is required to fully understand the response mechanisms, mechanical properties, and constitutive models of lightweight soil under the combined effects of complex environmental factors and dynamic loads. Additionally, there is a need for continued research into the design and construction methods of lightweight soil across various engineering settings. In conclusion, this paper serves as a valuable reference for investigating the dynamics of lightweight soil and its extensive application in geotechnical engineering.