Enzyme-microbe coupled fracturing fluid system and preparation method and applications thereof

The invention relates to a fracturing fluid system, in particular to a new aqueous fracturing enzyme-microbe coupled fracturing fluid system used in the petroleum and natural gas exploitation, wherein the chemical additives in the original aqueous fracturing fluid are replaced by the biological additives with the same function, and inoculating microbe degrading residue and gel are added to react so as to greatly increase the gel-breaking efficiency and reduce formation damage. The fracturing fluid system comprises the following components: 0.30-0.55wt% of vegetable gum polymer, 0.002-0.2wt% of biological bactericide, 0.025-0.05wt% of biological cleanup additive, 0.05-0.1wt% of ahead fluid biological optimizer, 0.05-0.1wt% of microbial enhanced production-increasing agent, 1-3wt% of clay stabilizer, pH regulator, 10-30mg/L of enzyme breaker and the balance water. The fracturing fluid system of the invention uses non-toxic and harmless natural products to the maximum to replace toxic and harmful chemical additi