A conjugate of polyethylene glycol and anesthetic having the structure of formula: wherein, PEG is polyethylene glycol residue with a molecular weight of 1-100KDa; R 0 is a C 1-6 alkyl; B is an anesthetic; a quaternary ammonium salt with a structure of is formed at the linking position between B and R 0, R s0 is selected from the group consisting of F-, Cl-, Br-, I-, methanesulfonate, ethanesulfonate, benzenesulfonate, citrate, lactate, succinate, fumarate, glutamate, citrate, salicylate, and maleate, preferably, R s0 is selected from the group consisting of F-, Cl-, Br-, I-, methanesulfonate, ethanesulfonate, and benzenesulfonate; and, A is a linking group selected from the group consisting of the structures shown by the following formula A 1 or A 2: wherein, R 1 and R 6 are independently selected from C 1-6 alkyl, preferably methyl, ethyl, or propyl, or R 1 and R 6 are independently selected from -(CH 2) i NHCO(CH 2) j -, and -(CH 2) i CONH(CH 2) j -, R 2 is selected from the group consisting of -C=O, -C=S, -0- or -S-; R 3 and R 7 are independently selected from the group consisting of -O- or -S-; R 4 or R 5 is independently selected from the group consisting of H, C 1-6 alkyl or halogen, preferably H, methyl or ethyl; R 8 or R 9 is independently selected from the group consisting of H, C 1-6 alkyl or -O(C=O)(CH 2) i CH 3, preferably H, methyl, ethyl, propyl, acetoxy, propionyloxy, and butyryloxy; i and j are integer independently selected from 0 to 6, preferably 1, 2, or 3; R 20 is R s1 is selected from the group consisting of H or C 1-6 alkyl, preferably H, methyl, ethyl or propyl; and the anesthetic is a local anesthetic of amides having the structure of formula: wherein, R 10 and R 11 are independently selected from the group consisting of H and C 1-6 alkyl; and, R 12 is selected from the group consisting of H and C 1-6 alkyl; and, R 13 and R 14 are independently selected from the group consisting of C 1-6 alkyl; or R 13 is selected from the group consisting of C 1-6 alkyl, and together with R 12 and R 14 forms a 5- to 8-membered ring. wherein, PEG is polyethylene glycol residue with a molecular weight of 1-100KDa; R 0 is a C 1-6 alkyl; B is an anesthetic; a quaternary ammonium salt with a structure of is formed at the linking position between B and R 0, R s0 is selected from the group consisting of F-, Cl-, Br-, I-, methanesulfonate, ethanesulfonate, benzenesulfonate, citrate, lactate, succinate, fumarate, glutamate, citrate, salicylate, and maleate, preferably, R s0 is selected from the group consisting of F-, Cl-, Br-, I-, methanesulfonate, ethanesulfonate, and benzenesulfonate; and, A is a linking group selected from the group consisting of the structures shown by the following formula A 1 or A 2: wherein, R 1 and R 6 are independently selected from C 1-6 alkyl, preferably methyl, ethyl, or propyl, or R 1 and R 6 are independently selected from -(CH 2) i NHCO(CH 2) j -, and -(CH 2) i CONH(CH 2) j -, R 2 is selected from the group consisting of -C=O, -C=S, -0- or -S-; R 3 and R 7 are independently selected from the group consisting of -O- or -S-; R 4 or R 5 is independently selected from the group consisting of H, C 1-6 alkyl or halogen, preferably H, methyl or ethyl; R 8 or R 9 is independently selected from the group consisting of H, C 1-6 alkyl or -O(C=O)(CH 2) i CH 3, preferably H, methyl, ethyl, propyl, acetoxy, propionyloxy, and butyryloxy; i and j are integer independently selected from 0 to 6, preferably 1, 2, or 3; R 20 is R s1 is selected from the group consisting of H or C 1-6 alkyl, preferably H, methyl, ethyl or propyl; and the anesthetic is a local anesthetic of amides having the structure of formula: wherein, R 10 and R 11 are independently selected from the group consisting of H and C 1-6 alkyl; and, R 12 is selected from the group consisting of H and C 1-6 alkyl; and, R 13 and R 14 are independently selected from the group consisting of C 1-6 alkyl; or R 13 is selected from the group consisting of C 1-6 alkyl, and together with R 12 and R 14 forms a 5- to 8-membered ring.