In order to improve the detection sensitivity of Raman spectrometer, a copper-based surface-enhanced Raman scattering film substrate was designed. A series of copper-titanium alloy films were obtained by controlling the magnetron sputtering parameters with Cu₄₀Ti₆₀ alloy target. The copper-based films with different structures were systematically studied. The effects of different sputtering parameters on surface enhanced Raman scattering (SERS） characteristics of the copper-based films were investigated. The optimal sputtering parameters for the preparation of SERS substrates were determined. The copper film obtained after dealloying has a porous structure and can form a high-intensity local electromagnetic field, that is, SERS "hotspots", thereby exhibiting excellent SERS enhancement performance. The substrate is low in cost and good in repeatability by magnetron sputtering, and can achieve sensitive detection and SERS enhancement factor up to 1.8×10⁷. It is one of the ideal choices for high performance SERS substrates and has a high application prospect.