Objective: The development of a method for detecting pesticide residues based on surface enhanced Raman scattering (SERS) substrate of MXenes (Ti3C2Tx) of two-dimensional nanoparticle materials. Methods: Firstly， a single layer of negatively charged MXenes two-dimensional material was prepared by fluorine salt etching method， and then synthesized 30 nm of gold nanoparticles (AuNPs) modified by the positively charged surfactant CTAC， and AuNPs/MXenes was prepared with MXenes loaded with AuNPs by electrostatic adsorption. Secondly， the concentration ratio of AuNPs and MXenes colloidal solutions was optimized with R6G as the Raman probe molecule. Thirdly， it is used for the detection of thiram. Results: The Raman enhancing factor of AuNPs/MXenes is 1.7×105， which showed good SERS activity. A linear relationship was constructed between the strength of the thiram Raman characteristic peak at 1 379 cm-1 and the logarithm of the thiram pesticide residue concentration， and the standard curve was obtained: y=888x+1 151， the coefficient R2 was 0.986， and the detection limit was 0.051 ng/mL， which was lower than the national standard of 5 ng/mL. The QuEChERS method was used to pretreat the citrus samples， and the SERS detection of thiram residue in the real citrus samples was realized， and the recovery rate ranged from 101.1% to 122.0%. Conclusion: The SERS substrate prepared based on the MXenes structure has potential for thiram detection in citrus samples.