The invention provides bright brush electroplating silver plating liquid. The bright brush electroplating silver plating liquid comprises, by mass concentration, 18g/L-25g/L of silver nitrate, 80g/L-200g/L of succinimide, 25g/L-40g/L of ammonium sulfite, 16g/L-21g/L of compound additives, 20g/L-35g/L of ammonium acetate, 25g/L-40g/L of sodium nitrate and 12.5g/L-22.5g/L of NH3.H2O. The compound additives comprise 8g-12g of fatty alcohol polyoxyethylen ether, 0.07g-0.2g of N,N- dimethylformamide and 0.1g-0.3g of polyoxyethylene octyl phenol ether-10. The bright brush electroplating silver plating liquid has the advantages of being stable in chemical property, being free of toxicity, being environmentally friendly and the like. A silver plating metal layer which is excellent in electrochemical performance, uniform and compact in structure and high in adhesive force can be formed on the surface of a copper-based material. Operation is easy, convenient and fast, the cost is low, and the bright brush electroplating silver plating liquid is suitable for large-scale industrial application. In addition, the invention provides a preparation method and an application method of the bright brush electroplating silver plating liquid.