The present invention provides a low specific surface area TiB2 TiC composite ceramic material and its preparation method, belonging to the field of ceramic material technology. The invention disperses the boron source, titanium source and carbon source in the polymer grid formed by the polymer grid agent under the action of the initiator to obtain the polymer grid gel precursor with uniform mixing of titanium, boron and carbon elements. The polymer grid gel precursor not only ensures the uniform mixing of reaction materials, but also obtains the micro uniformly mixed TiB2 TiC powder during the sintering process. At the same time, during the sintering process of the gel precursor, the carbon element in the grid reduces the specific surface area of the product TiB2 and TiC during the sintering process, so as to obtain the uniformly mixed TiB2 TiC composite ceramic material with low specific surface area.