The inverse kinematics problem involves the study that the inverse kinematics solver needs to calculate the values of the joint variables given the desired pose of the end-effector of a robot. However, to apply to seven-degree-of-freedom robots with arbitrary configuration, analytical methods need to fix one joint and set an increment when the current value fails to solve the inverse kinematics problem. Although numerical methods based on inverse differential kinematics are efficient in solving the inverse kinematics problem of seven-degree-of-freedom robots with arbitrary geometric parameters, they are deficient in numerical stability and time-consuming for convergence to one solution governed by the initial guess. In order to reduce the execution time of an inverse kinematics solver, this article introduces a speedup method for analytical and numerical methods, which can improve their performance.