Method for realizing double patterning process of contact pattern

The invention discloses a double-patterning process implementation method of a contact pattern, which comprises the following steps of: S1, depositing three layers of hard masks, performing a Photo exposure process on the three layers of hard masks, and etching to form a first layer of pattern; s2, performing isolation film deposition on the first layer of pattern to form an isolation film; s3, etching the isolating membrane; s4, etching the first layer of hard mask; s5, removing the isolating membrane by using a Clean process; s6, performing rotary hard mask deposition on the second layer of hard mask, and performing etch-back to form a rotary hard mask; s7, etching the first layer of pattern, and removing the edge area of the pattern; s8, performing wet etching on the first layer of hard mask; s9, removing the first layer of pattern; s10, removing the rotary hard mask; s11, etching the second layer of hard mask mold to form double contacts; and S12, removing the mold of the second layer of hard mask to comp