Corrosion inhibitor for NaCl salt water workover fluid

The invention discloses a corrosion inhibitor for a NaCl salt water workover fluid. The corrosion inhibitor comprises components as follows: 10-35 parts of guar gum, 50-70 parts of trigonella foenum-graecum powder and 15-20 parts of agar powder. According to the corrosion inhibitor for the NaCl salt water workover fluid, the guar gum, the trigonella foenum-graecum powder and the agar powder which are commercially available in the market are mixed in certain ratio, composite powder is prepared, and the corrosion inhibitor suitable for preparation of the NaCl salt water workover fluid is obtained; the three raw materials are non-toxic, have sufficient sources and are low in cost, and the preparation method is simple; further, the compatibility of the NaCl salt water workover fluid prepared from the corrosion inhibitor and a NaCl aqueous solution is good, a homogeneous and stable system can be formed, the problem of severe corrosion on equipment for well control as well as steel products such as pipe columns and the like in manifolds and shafts due to the adoption of the conventional NaCl salt water workover fluid is effectively solved, the corrosion speed is lower than that of fresh water, and the service life of each steel product is prolonged; the workover fluid has the properties that viscosity is improved, corrosion inhibition is realized and the compatibility is good.