K type thermocouple alloy wire and its production method

The invention relates to the technical field of a thermocouple, in particular to a K-type thermocouple alloy wire and a preparation method thereof. The K-type thermocouple alloy wire is provided with a positive pole and a negative pole, wherein the positive pole is a thermocouple alloy wire made of a nickel chrome material; the negative pole is the thermocouple alloy wire made of a nickel silicon alloy material; the nickel chrome material comprises the following chemical compositions in percentage by mass: 9.5 percent of Cr, 1.0 percent of Co, 0.40 percent of Si, 0.05 percent of Ca, 0.05 percent of Y, 0.05 percent of misch metal, and the balance being Ni; and the nickel silicon alloy material comprises the following chemical compositions in percentage by mass: 0.29 percent of the Co, 2.5 percent of the Si, 0.55 percent of Mn, 0.05 percent of the Ca, 0.05 percent of the misch metal, and the balance being the Ni. As service life of the thermocouple is prolonged, cost of raw materials and products can be saved f