A new strategy for the simultaneous determination of hydride-generation and non-hydride-generation elements in seafood by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was proposed based on a multimode sample introduction system (MSIS). After the seafood was digested by the microwave digestion system， the hydride-generation elements As， Se， Sn， Sb， Hg and the non-hydride-generation elements Ti， V， Cr， Mn， Fe， Co， Ni， Cu， Zn， Mo， Sr， Cd， and Pb in the digestion solution were simultaneously determined by ICP-MS/MS in the dual mode of MSIS. O₂ and NH₃/He were added to the collision/reaction cell as reaction gases， mass shift， on-mass and charge transfer method were used to eliminate the spectral interference， and the internal standard element with the same mass spectral behavior as the analyte was selected to correct the matrix effect. The accuracy and reliability of the analytical method was assessed by the analysis of the standard reference material GBW10024 (scallop). The results showed that the analytes achieved excellent linearity with correlation coefficients R≥0.9996， the limit of detection (LOD) was 0.02-1.61 ng/L， the spike recovery was 94.0%-108%， and the relative standard deviation (RSD) was 2.1%-7.1%. The method has the advantages of simple and rapid operation， high sensitivity， good accuracy and precision， and can be used for high-throughput detection of hydride-generation and non-hydride-generation elements in seafood.