The analysis of the influence of the array installation errors on the angle measurement accuracy of the phased array radar is important for the research and development of the high-performance phased array radar. The array installation errors-angle measurement accuracy model of the phased array radar is established. The angle measurement accuracy of the phased array radar with inclination error, role-angle error and azimuth normal error is studied by simulation respectively. The precision of the deduced concise formula arrivers accuracy level of 0.001° compared with the angle measurement accuracy error caused by array installation errors. The deduced formula and conclusion offers theoretical basis and engineering guidance for assigning the accuracy index of array installation and analyzing the accuracy out-of-tolerance problem of angle measurement.