The present invention relates to a liquid crystal compound having a structure as shown by formula I, wherein R is selected from H and alkyl or alkoxy containing 1-12 carbon atoms in which one or more H are unsubstituted or substituted with halogens; A1, A2 and A3 are each independently selected from: a single bond, 1,4-cyclohexylene, 1,4-phenylene, wherein hydrogen in 1,4-phenylene may be each independently substituted with one or more halogens; and Z1 and Z2 are each independently selected from a single bond or —(CH2)2—. The compound of the invention has the characteristics of low rotational viscosity, large dielectric anisotropy, good mutual solubility and stability. The driving voltage of a device can be remarkably reduced after the compound is added to a composition. Thus, the compound of the invention has prosperous applications in LCD industry.