The invention relates to a chitosan plural gel foaming agent suitable for a female sperm shielding and killing dual-contraception effect and a preparation method thereof, and belongs to the technical field of foaming agent production. The chitosan plural gel foaming agent suitable for the female sperm shielding and killing dual-contraception effect has a dual-contraception effect of vagina shielding and vagina sperm killing, and meanwhile has a fungal-infection-resistant effect. The foaming agent forms a medicament liquid by consisting of a matrix, a surface active agent, an auxiliary medicament, a cosolvent, an acidifier, a foaming agent, a foam stabilizing agent and a solvent, and the foaming agent and a propellent form a plural gel foaming agent according to the weight proportion of (100:10) to 20. The preparation method comprises the following steps: dissolving chitosan and carbomer into a citrate buffer solution with a certain amount; blending, heating to 80 DEG C to dissolve completely, adding the surface active agent so as to obtain a solution A; dissolving borneol, menthol crystal and stearic acid into glycerol, dissolving fully, and filtering so as to obtain a solution B; adding the solution B into the solution A, mixing fully, adding citric acid and SLS (sodium lauryl sulfate), supplying the buffer solution to the required weight, carrying out vacuum homogenizing for 2 hours, thereby obtaining the gel foaming preparation, and then adding the propellent.