Temperature-resistant and salt-resistant cationic guar gum fracturing fluid and preparation method thereof

The invention provides a temperature-resistant and salt-resistant cationic guar gum fracturing fluid and a preparation method thereof. The cationic guar gum fracturing fluid comprises the following components in percentage by mass: 0.3%-1% of cationic guar gum fracturing fluid, 0.3%-2% of anionic chelating agent, 0.3%-0.6% of organic cross-linking agent and the balance of water for liquid preparation. The invention also relates to a preparation method of the temperature-resistant and salt-resistant cationic guar gum fracturing fluid. The anionic chelating agent is added into the cationic guar gum fracturing fluid, the anionic chelating agent can reduce the influence of metal ions on the performance of the fracturing fluid, and meanwhile, high-valence anions in the anionic chelating agent achieve secondary crosslinking on the hydroxypropyl guar gum fracturing fluid crosslinked by the organic crosslinking agent through the electrostatic attraction effect; under the condition that the concentration of the guar g