The invention discloses a preparation method for in-situ generation of a (Ti, W) C reinforced WC-Ni3Al composite material by adding Ti powder. The method comprises the following preparation steps: preparing Ni3Al powder by mechanical alloying, wherein the Ni3Al powder comprises Ni, Al, Cr, Mo and B; the raw material powder is placed in a ball mill for dry ball milling, and Ni3Al intermetallic compound powder is prepared; ni3Al intermetallic compound powder, titanium powder and WC powder are placed in an organic solvent to be subjected to wet ball milling, mixed slurry is prepared, then the mixed slurry is dried, pulverized and sieved, and mixed powder is obtained; and sintering to obtain the product. On the premise that titanium powder is added, (Ti, W) C is generated in a WC matrix by adopting an in-situ generation method, the added Ti powder firstly consumes part of O elements in the sintering process to form an oxide of Ti, then TiC is formed at high temperature, and then the TiC and WC form a (Ti, W) C solid solution.