Surface Enhanced Raman Scattering (SERS) refers to the phenomenon that the Raman scattering signal of molecules adsorbed on some rough metal surfaces can be significantly enhanced. The combined effect of electromagnetic enhancement and chemical enhancement is widely recognized as the SERS mechanism by researchers. SERS substrates can be divided into simple SERS substrates and composite SERS substrates. Simple SERS substrates include metal electrode substrates, metal collosol substrates, and metal thin film substrates. Meanwhile, composite SERS substrates include bimetal composite substrates, oxide composite substrates, and flexible material composite substrates. Nono silver is a common-used metal SERS substrate.SERS is an important method to study the structure of the ionic liquid. The ionic liquid often works in a temperature range from room temperature to 100 ℃. However, there are few studies reported on the influence of temperature on the SERS effect. In the present study, firstly, silver SERS substrates are prepared by the constant-current electrodeposition method with current density of 0.5 A/dm² at 35 ℃ for depositing 900 s. Then, the prepared silver substrates are roasted at 100 ℃ ~400 ℃, the influence of the roasting temperature on the morphology of the substrates is investigated, and the corresponding SERS mechanism is discussed. Finally, the prepared silver substrates are applied for the in-situ SERS spectra detection on 1-ethyl-3-methylimidazolium chloride (EMImCl) ionic liquid at different temperatures and the SERS effect is analyzed.The results show that in the substrate, the silver atoms form the dendrite consisting of a trunk and symmetric branches on both sides. The surface plasmon resonance generated by the dendrite gaps causes strong electromagnetic field, which can enhance the Raman signal of the adsorbed molecule. On the other hand, the branches have high curvature tips, which can produce lightning rod effect and improve the SERS performance of the substrates.In fact, the substrate is in an unstable metastable state, but the mobility of the silver atoms at room temperature is very weak. However, higher temperature can lead to stronger mobility of the silver atoms, causing the substrate transit to a more steady state with smaller free energy. Therefore, roasting process can make the nanoparticles reintegrate. As a result, the silver atoms in the high curvature part of dendrite can diffuse, causing the separation of grains. It is found that when the roasting temperature is 300 ℃, the tips of the branches begin to disappear and agglomerate. When the roasting temperature is raised to 400 ℃, the dendrites still exist, but the branches become thick and completely agglomerate, and it is noteworthy that very small spherical silver nanoparticles are formed on the surface of the dendrites.With R6G used as probe molecule, the SERS effect of the prepared silver substrates before and after roasting is investigated. It is found that the enhancement factor of the silver substrate decreases with the increase of roasting temperature. The enhancement factor of substrates before roasting is 1.62×10⁵. When the roasting temperature is 400 ℃, the enhancement factor reaches 2.16×10⁴, indicating that the SERS effect of the prepared silver substrates is still obvious. It is believed that changes of substrates′ structure reduce the “hot spot” area on the substrate after roasting. When the roasting temperature reaches 400 ℃, the newly generated spherical silver nanoparticles provide new “hot spot”, so that the substrates after high temperature calcination still have the SERS effect. However, the surface areas of the newly generated silver nanoparticles are very small, which greatly reduces the number of the adsorbed molecules, making the SERS effect weakened.The results of the in-situ Raman spectra detection on EMImCl with using the prepared SERS substrates show that the Raman spectrum signal is significantly enhanced. As the detection temperature increases from room temperature to 100 ℃, the ability of the substrate to enhance the Raman spectrum signal is not significantly weakened.