Abstract: An attitude feedback based method for establishing the closed-loop control system of spherical parallel mechanism (SPM)is proposed to circumvent the difficulty caused by the complex,three-dimensional,nonlinear and strongly coupled relationship between the input and output of the mechanism.SPM,then,is employed to the design of bionic eye which emulates the function of human's eye but is bigger than it in size,and incorporates the interface of the signal of control and video.In addition,the real-time online calculation of the inverse kinematics and the scheme of the closed-loop control is conducted on DSP(digital signal processor).Finally,the experimental results substantially confirm that the improved positioning precision of the bionic eye is obtained by introducing the proposed algorithm.