The invention provides a method and a system for acquiring the dynamic error of an angle intersection measurement system. The method comprises the following steps: acquiring the measured coordinates of a to-be-measured target output by an angle intersection measurement system; obtaining the theoretical coordinates of the to-be-measured target when a first observation station completes measurementaccording to the position of each observation station, the observation angle output by each observation station, the time synchronization error between the observation stations and the movement speedof the to-be-measured target; obtaining dynamic error caused by the time synchronization error according to the measured coordinates and the theoretical coordinates; obtaining dynamic error caused bythe observation angle error according to the observation angle error of each observation station and an observation angle error propagation matrix of the angle intersection measurement system; and obtaining the dynamic error of the measurement system according to the dynamic error caused by the time synchronization error and the dynamic error caused by the observation angle error. According to thescheme, error analysis is performed from a dynamic error generation source, and the dynamic error is calculated by utilizing the geometrical relationship corresponding to the measurement principle ofthe measurement system, so that the result is more comprehensive and effective.