To improve the assembly precision of mobile phone camera, a small-sized parallel manipulator (SSPM) used for precise assembly was developed, and a calibration test and mechanical error analysis were conducted. First, an error model and the forward-inverse kenametic model were derived using numerical method, and the connection problem between the error model and the kenametic model was studied. Second, a calibration procedure was designed and a calibration test was conducted on coordinate measuring machine (CMM). Finally, an analysis on the error sources of SSPM was conducted from the mechanical view, the effect of SSPM’s structure on the gap error was analyzed, and a repeatability test of SSPM was conducted to represent the gap error. After calibration and mechanical error control, the maximum displacement error decreases from 0.345 9 mm to 0.012 1 mm, the maximum angular error decreases from 0.007 3 rad to 0.001 1 rad, and the repeatability of SSPM is 0.004 8 mm. Experimental results show that the calibration and mechanical error control method on SSPM can effectively improve the accuracy of SSPM.