Guanidine gum fracturing fluid cross-linking agent and preparing method and application thereof

The invention provides a guanidine gum fracturing fluid cross-linking agent. The cross-linking agent is prepared from, by weight, 45-60 parts of 1,2-glycol, 5-20 parts of sugar, 15-35 parts of borax and 3-10 parts of titanate. The invention further provides a preparing method of the guanidine gum fracturing fluid cross-linking agent. The preparing method comprises the steps that 1,2-glycol, the sugar, borax and titanate are weighed; at the room temperature, 1,2-glycol is added into a reaction kettle, the sugar and titanate are added in a stirred mode, temperature is raised, and the reaction is carried out until a settled solution is obtained; borax is added into the reaction kettle, the temperature is raised further, and the reaction is carried out until yellow supernatant liquid is obtained; the temperature is lowered to obtain the cross-linking agent. The invention further provides application of the guanidine gum fracturing fluid cross-linking agent to preparation of low-concentration guanidine gum fractur