AbstractA novel group of nonionic gemini surfactant (GTPEA) with ethylidene spacer structure was prepared from glucose‐lactone, triethylenetetramine, alkyl epoxy polyether and acyl chloride of different alkyl chain lengths. The chemical structure of GTPEA were characterised by Fourier‐transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) and high‐resolution mass spectrometry (HRMS). The thermal properties of the three surfactants were characterised by thermogravimetric analysis (TGA). The critical micelle concentrations (cmc values) of GTPEA with different hydrophobic chain lengths were measured using the Wilhelmy plate method (cmc: 1.58 × 10−5 to 5.01 × 10−6 mol/L). The solubilisation, emulsification and solubilisation performance tests showed the excellent surface properties of nonionic gemini surfactants. GTPEA‐12 with a hydrophobic carbon chain length of 12 carbon atoms was selected to explore the dispersing performance of surfactants on disperse dyes and the levelling performance of polyester fibre disperse dyes. The test results have shown that the dispersion force was 96%, and the particle size of 0.1 g disperse dye was 196 nm in 100 ml of 4 g/L GTPEA‐12 solutions. Finally, GTPEA‐12 was used as a levelling agent in the dispersion dyeing of polyester fabrics. GTPEA‐12 of 0.1 g/L can provide an excellent levelling effect of S(λ) = 0.026 for polyester and has little impact on the colour yield (K/S = 5.0) of polyester fabric.