Formula of foam extinguishing agent containing biosurfactant and preparation method for foam extinguishing agent

The invention relates to a foam extinguishing agent containing a biosurfactant and a preparation method for the foam extinguishing agent. The problems that an existing foam extinguishing agent is liable to pollute the environment and the preservation time is short are mainly solved. The foam extinguishing agent containing the biosurfactant comprises, by weight, 10%-30% of rhamnolipid, 3%-15% of sophorolipid, 0.1%-0.5% of a thickening agent, and the balance water. The preparation method for the foam extinguishing agent comprises the steps that under the stirring condition, the rhamnolipid is added into a certain amount of water, and after even stirring, the sophorolipid is added; after even mixing, the mixture is heated to 80 DEG C-90 DEG C in a reaction kettle; after the mixture is cooled to the room temperature, sodium alginate is dissolved with 10% of water and added to the reaction kettle; and the balance water is added as a complement, and the mixture is mixed evenly. According to the foam extinguishing a