The invention discloses a silicon carbide crystal whisker in-situ composite lithium ceramic material which comprises a base material and a bonding agent, wherein the base material comprises the following components: 15-32wt% of a lithium mineral raw material, 25-50wt% of a clay raw material, 2-10wt% of quartz powder, 7-28wt% of metal silicon powder and 3-12wt% of a carbon source material; the amount of the bonding agent accounts for 6-12wt% of the base material; and the silicon carbide crystal whisker in-situ composite lithium ceramic material is prepared by preparing the base material and thebonding agent into a crude blank and by performing carbon burying sintering. In addition, the invention further discloses a preparation method of the silicon carbide crystal whisker in-situ compositelithium ceramic material. By adjusting formula systems, doping the metal silicon powder and the carbon source material and implementing carbon burying sintering, a silicon carbide crystal whisker isintroduced into a lithium ceramic in an in-situ synthesis method, and thus the lithium ceramic material with high heat conductivity and high strength is prepared.