Liquid crystal composition and liquid crystal display device

A liquid crystal composition, wherein the liquid crystal composition comprises at least one compound of general formula I and at least one compound of general formula II:

• wherein, R1 represents any one of C1-12 halogenated or unhalogenated linear alkyl, C3-12 halogenated or unhalogenated branched alkyl,
• wherein, one or at least two nonadjacent —CH2— group in the C1-12 halogenated or unhalogenated linear alkyl and C3-12 halogenated or unhalogenated branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO— group;
• R11 represents
• X1 represents —O— or —S—, n11 represents 0, 1, 2, 3 or 4;
• ring
• represents
• R2 and R3 each independently represents any one of C1-12 linear alkyl, C3-12 branched alkyl,
• wherein, one or at least two nonadjacent —CH2— group in the C1-12 linear alkyl and C3-12 branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO— group;
• ring
• represents
• wherein one or at least two —CH2— in
• can each be independently replaced by —O—, one or at least two single bond in the rings can each be independently replaced by double bond;
• one or at least two —H on
• can each be independently replaced by —F, —Cl, —CN, —CH3 or —OCH3, one or at least two —CH═ in the rings can each be independently replaced by —N═;
• L1-L4 each independently represents halogen atom;
• X2 represents —O— or —S—;
• X3 represents —O— or —CH2—;
• Z1 represents single bond, —CO—O—, —O—CO—, —CH2O—, —OCH2—, —CH═CH—, —C≡C—, —CH2CH2—, —CF2CF2—, —(CH2)4—, —CF2O— or —OCF2—;
• n1 represents 0, 1 or 2, when n1 represents 2, ring
• can be the same or different, Z1 can be the same or different;
• and
• n2 represents 1 or 2.