Disclosed herein are a highly dense and nano-grained NTC thermistor thick film and a method for preparing the same, and specifically, an NTC thermistor thick film vacuum deposited by spraying a spinel grained ceramic powder containing Ni and Mn on one side of the surface of a substrate using a room temperature powder spray in vacuum (AD) and a method for preparing the same. According to the present invention, a room temperature powder spray in vacuum (AD) may be used to perform a rapid deposition of NTC thermistor thick films and prepare a highly dense ceramic thick film, the NTC characteristic constant B which would be obtained by doping may be maximized without doping, demagnetization may be obtained without any additional heat treatment, and thus limitations on substrate that the conventional art has may be completely overcome.