An isolated polypeptide which has a structure as shown in formula V: X 0 -Z-X A -X E wherein, X 0 or X A is not present, or is 1, 2, 3, or 4 amino acid residues; X E is not present or is a cell-penetrating element; Z is a YAP inhibiting polypeptide having an introduced intra-chain disulfide linkage, wherein the YAP inhibiting polypeptide has the amino acid sequence shown in formula Va: Z1-Z2-Z3-Z4-Z5-Z6-Z7-Z8-Z9-Z10-Z11-Z12-Z13-Z14-Z15-Z16 Formula Va wherein, Z1 is V or A; Z2 is P; Z3 is L or chlorophenylalanine; Z4 is R, K, A or not present; Z5 is L or Nle; Z6 is R or K; Z7 is K, R, Orn or Dab; Z8 is L or Nle; Z9 is P; Z10 is any natural or unnatural amino acid, and preferably D, A, V, L, I or E; Z11 is S; Z12 is F; Z13 is F, L, chlorophenylalanine or not present; Z14 is K, R or not present; Z15 is P or not present; Z16 is P or not present; and the intra-chain disulfide linkage comprising a first amino acid B1 and a second amino acid B2, wherein the first amino acid B1 of disulfide linkage is located between any two amino acids in a first segment formed by Z1 to Z8 in the basic sequence or is located before the first amino acid of the first segment, and the second amino acid B2 of disulfide linkage is located between any two amino acids in a second segment formed by Z9 to Z16 in the basic sequence or is located after the last amino acid of the second segment. X 0 or X A is not present, or is 1, 2, 3, or 4 amino acid residues; X E is not present or is a cell-penetrating element; Z is a YAP inhibiting polypeptide having an introduced intra-chain disulfide linkage, wherein the YAP inhibiting polypeptide has the amino acid sequence shown in formula Va: Z1-Z2-Z3-Z4-Z5-Z6-Z7-Z8-Z9-Z10-Z11-Z12-Z13-Z14-Z15-Z16 Formula Va wherein, Z1 is V or A; Z2 is P; Z3 is L or chlorophenylalanine; Z4 is R, K, A or not present; Z5 is L or Nle; Z6 is R or K; Z7 is K, R, Orn or Dab; Z8 is L or Nle; Z9 is P; Z10 is any natural or unnatural amino acid, and preferably D, A, V, L, I or E; Z11 is S; Z12 is F; Z13 is F, L, chlorophenylalanine or not present; Z14 is K, R or not present; Z15 is P or not present; Z16 is P or not present; and the intra-chain disulfide linkage comprising a first amino acid B1 and a second amino acid B2, wherein the first amino acid B1 of disulfide linkage is located between any two amino acids in a first segment formed by Z1 to Z8 in the basic sequence or is located before the first amino acid of the first segment, and the second amino acid B2 of disulfide linkage is located between any two amino acids in a second segment formed by Z9 to Z16 in the basic sequence or is located after the last amino acid of the second segment. Z1 is V or A; Z2 is P; Z3 is L or chlorophenylalanine; Z4 is R, K, A or not present; Z5 is L or Nle; Z6 is R or K; Z7 is K, R, Orn or Dab; Z8 is L or Nle; Z9 is P; Z10 is any natural or unnatural amino acid, and preferably D, A, V, L, I or E; Z11 is S; Z12 is F; Z13 is F, L, chlorophenylalanine or not present; Z14 is K, R or not present; Z15 is P or not present; Z16 is P or not present; and the intra-chain disulfide linkage comprising a first amino acid B1 and a second amino acid B2, wherein the first amino acid B1 of disulfide linkage is located between any two amino acids in a first segment formed by Z1 to Z8 in the basic sequence or is located before the first amino acid of the first segment, and the second amino acid B2 of disulfide linkage is located between any two amino acids in a second segment formed by Z9 to Z16 in the basic sequence or is located after the last amino acid of the second segment.