Abstract: A carbon composite ceramic linear resistor and a preparation method thereof are provided. The preparation method includes the following steps. Bentonite, silicon carbide and nano carbon black are mixed to obtain a powder mixture. The powder mixture and ethyl alcohol are mixed uniformly, and dried to obtain a uniformly mixed powder. A binder solution is added to the uniformly mixed powder to obtain a mixture. The green body obtained by die-pressing is heated to a temperature ranging from 1150 Celsius degrees (° C.) to 1300° C. in a nitrogen-containing gas atmosphere, and the temperature is kept to obtain a sample. The sample is ground to obtain a ground sample. Then aluminum is sprayed on the ground sample to obtain the carbon composite ceramic linear resistor. The preparation method can be used to reduce electrical resistivity and increase thermal shock resistance of the carbon composite ceramic linear resistor.