Positive temperature coefficient thermistor and preparation method thereof

The method comprises the following steps: according to the stoichiometric ratio of cations in CaxBayPb1-x-yTiO3, mixing a calcium salt, a barium salt, a lead salt and a titanium salt to obtain a main material, carrying out primary ball milling, drying and sieving the slurry obtained after ball milling, then pre-sintering to obtain a blank, adding a manganous nitrate solution into the blank, and carrying out sintering to obtain the positive temperature coefficient thermistor. The method comprises the following steps: carrying out primary ball milling on a blank body, carrying out secondary ball milling on the blank body, adding an auxiliary material into the main material before the primary ball milling, and/or adding the auxiliary material into the blank body before the secondary ball milling, the auxiliary material comprises aluminum oxide, and the ratio of the amount of substance of the aluminum oxide to the amount of substance of the titanium salt is (0.008-0.016): 1; and discharging after secondary ball m