A fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS) was developed for the qualitative analysis of unknown components in an imported aluminum sealer as surface treatment agent,which was processed from a variety of ingredients.Naphthalene sulfonate,nickel acetate,sodium benzoate and other components were discovered in this kind of product.Through the precise molecular ion data derived from FT-ICR-MS analysis and the isotope fine structure,the unknown material ion formula was inferred.Then,combined with inductively coupled plasma mass spectrometry(ICP-MS) and gas chromatography-mass spectrometry(GC-MS) analysis,the structures of unknown components were deduced.In addition,another two groups of unknown masses in the mass spectra with a difference of 62:234.8,296.8,358.9 and 410.7,472.7,534.7,combined with two-stage mass spectrometry,could be concluded to derive from the polymerization of nickel acetate with formic acid and benzoic acid,and some dimer and trimer ions were produced simultaneously.The attribution of all ions in the mass spectra of this product was certified,and most of the components in this product were analyzed.A new train of thought and method for the analysis of unknowns in chemical products was provided in this paper,and it could be used for the qualitative identification of unknowns in complex systems,and the ionization law about the metal ion of nickel combined with organic acid ionized in mass spectrometry was also founded.