Abstract: In heavy ion collisions(HICs), the production of light particles plays an important role in extracting information about the equation of state(EoS) of nuclear matter. Based on the Ultra-relativistic Quantum Molecular Dynamics(UrQMD) model, the effect of the sequential decay on the collective flows and the nuclear stopping power of light particles in Au+Au collisions at intermediate energies were investigated, with the statistical decay model GEMINI++ is used to process the secondary decay of the primary fragments. It is found that due to the memory effect and the daughter nuclei produced by decay inherent part of the dynamic information of the parent nucleus, the experimental data can be better described by considering the sequential decay. And the influence of the sequential decay on the observables weakens with the increase of the collision energy. The results highlight that the sequential decay and the production of light particles in HICs have an obvious effect on the observables sensitive to the EoS, and these effects should be considered when adopting these observables to extract the information of the EoS.