In order to slow down oxidation of silver particles, improve stability and maintain high signal intensity, silver particles were coated with graphene. An experimental study was carried out to slow down the oxidation rate of silver particles by using ultra-thin graphene. In the experiment, the concentration of R6G solution as low as 10-11mol/L could still be detected after the substrate was placed for one month. The results show that the presence of graphene makes the graphene/silver particle composite structure possess both electromagnetic and chemical enhancement mechanisms. The detection sensitivity of the substrate is improved. The enhancement effect of the basement has nearly doubled with the decay rate of time. The stability of Raman substrate is improved. This method is economical and simple. It can be widely applied to various silver-based Raman substrates and will not destroy the original structure of the base.