The invention relates to a gemini amphiphilic surfactant as well as a preparation method and application thereof. The preparation method comprises the following steps of: adding n-octadecylamine and 3-chloro-2-hydroxy propyl sulfonic acid sodium of which the amount ratio is 1:(1.2-1.3) into a solvent containing a phase transfer catalyst to perform heating and refluxing, and standing for a night; adding a pH regulator into a reaction generated solution, adjusting the pH value of the system to be 8-9, and adding 1,2-dichlorethane, wherein the added amount of the 1,2-dichlorethane is metered according to the amount ratio of the n-octadecylamine to the 1,2-dichlorethane of 2:1 to 5:2; heating, refluxing, and standing for a night; and removing the solvent from the reaction generated solution through reduced pressure distillation to obtain the gemini amphiphilic surfactant. The gemini amphiphilic surfactant is used by compounding with sec-alkyl sodium sulphonate and sorbitol anhydride single oleate, the mineralization degree of the surfactant at 60 DEG C reaches 50000mg/L, and the interfacial tension with crude oil can reach 10<-3>mN/m, so that the crude oil recovery ratio can be effectively improved.