The invention discloses a TCP search optimization method under a high performance calculating network; the method comprises the following steps: 1, in TCP conversation processing, preferably calculating TCP conversations to obtain 32-bit short signatures if the TCP conversation order of magnitude is at the million level, carrying out XOR for the front 16-bit and rear 16-bit of the 32-bit short signatures obtained on the previous basis if the TCP conversation order of magnitude is at 100-million level, thus obtaining 16-bit short signatures; 2, respectively using the 32- bit short signatures and the 16-bit short signatures to replace a TCP tetrad identification TCP conversations; 3, building corresponding relations between the front P TCP conversation short signatures and Hash slots one by one; mapping the front P TCP conversation short signatures and Hash slots one by one if arrived TCP conversations exceed P, and assigning the TCP conversation short signatures (starting from P+1) from a TCB pool to a conflict list. The method can reduce the searching taken cache size, and can reduce the Hash conflict probability.