Abstract: The functional relationship between Clens structure parameters and point accuracy is given using the transfer matrix method. Based on this formula, the influence of structural parameters, including the distance d between the point of the incident fiber and the inclined surface, the refractive index of the Clens lens nl, the inclination angle θ between the optical end surface and the Clens end surface, the spherical curvature radius R and the length L, on the point accuracy are discussed. The calculation results show that when d is fixed, the adjustment ranges of R and L are both small. For example, when d is 0.2 mm, the changes of point accuracy caused by R and L are 0.019° and 0.03° respectively. This is because the focal length f is related to nl, R, and L and restricts each other, so that the point accuracy changes less. It is calculated that when the f is 0mm, 0.1mm, and 0.2mm respectively, the point accuracy corresponding to the maximum working distance is -0.493°, -0.257°, -0.03°.The reason is that among the parameters of R, L, and d, point accuracy can be changed effectively when at least any two of the parameters be changed at the same time. According to the point accuracy formula, the point accuracy of different types of Clens can be analyzed and a suitable optimization method can be obtained.