利用折射率椭球理论研究了各向异性晶体的平板负折射成像。研究结果表明:单轴晶体的负折射现象是由晶体的光学各向异性所引起的,属于单轴晶体的本质特性;单轴晶体的切角和双折射率是产生负折射的关键因素;各向异性晶体在一定的前提条件下可以实现平板负折射二次成像。最后通过钒酸钇(YVO4)和方解石(CaCO3)晶体对这套理论进行了实验验证。 The negative refractive imaging of anisotropic crystal was studied by using the theory of refractive index ellipsoid. The results show that the negative refraction phenomenon of uniaxial crystal is caused by the optical anisotropy of the crystal and belongs to the essential property of uniaxial crystal. The chamfer and birefringence of uniaxial crystal are the key factors of negative refraction. To the opposite sex crystal under the premise of certain conditions can be flat plate negative refraction secondary imaging. Finally, this theory is validated by YVO4 and CaCO3 crystals.