In order to solve the problem of operating precision analysis considering multiple error sources of serial robots, an operating precision analysis method combined Monte Carlo algorithm with pose error model of robot end-effector is proposed. Firstly, the pose error model of robot end-effector is built based on the MCPC method. Then, the error sources which have a main influence on the operating precision of robot end-effector are analysed in detail. At last, the Monte Carlo algorithm is used to analyse the error probabilistic characteristics of robot end-effector considering multiple error sources, which can validate the precision design of mechanical arms and provide theory basis to distribute the error limits of error sources reasonably.