Rapid and sensitive detection of phosphate is of great significance for ensuring water safety and preventing eutrophication. In this study, we prepared Au@PATP@Ag NRs core-shell structures using 4-aminothiophenol (PATP) as an internal standard signal molecule to enhance the stability of the SERS signal. Based on the protective effect of ZIF-8 on the internal Au@PATP@Ag NRs and the phosphate-induced decomposition of ZIF-8, a phosphate SERS sensor (Au@PATP@Ag@ZIF-8) with high sensitivity, selectivity and stability was designed. This method exhibited a good linear range of 0.1-125 μM and a detection limit of 30 nM. Furthermore, the developed sensor (Au@PATP@Ag@ZIF-8) was effectively applied to assess PO