Preparation method of sulfonate anionic-nonionic Gemini surfactant

The invention discloses an efficient preparation method of a sulfonate anionic-nonionic Gemini surfactant, which comprises the following steps: in a closed reaction device, carrying out esterification reaction on ethylene glycol and maleic anhydride to obtain maleic monoester, then carrying out esterification reaction on maleic monoester and isomeric fatty alcohol ether to obtain a series of maleic diester, and finally, taking sodium hydrogen sulfite as a sulfonating agent to obtain the sulfonate anionic-nonionic Gemini surfactant. The preparation method comprises the following steps: sulfonating maleic acid diester, extracting the obtained mixture for three times by using an extracting agent to remove an unreacted oil phase, carrying out rotary evaporation to remove water in a water phase, neutralizing by using an ethanol solution of sodium hydroxide, adding sufficient ethanol, filtering to remove inorganic salt, and finally carrying out rotary evaporation to remove a solvent, thereby obtaining the series of