Abstract: In this paper, a low angle tracking error analysis method based on two-way parabolic equation (2WPE) model is proposed, to consider the complicated environmental impacts on estimation error of low angle target. According to the two-way parabolic equation, a multipath effect model is established, which takes into account the influences of geographical meteorological conditions and radar parameters. It is used to analyze the interaction mechanism between radio waves and the environment, and also calculate the propagation factor of environment. Accordingly, the propagation factor is constructed to modify the traditional angle measurement model, to gain deterministic simulation analysis ability under complex environment. In this paper, low angle tracking errors under some typical environments, such as smooth sea, rugged terrain and so on. The results show that the radar transmit beam width, radar signal frequency and the geographical environment around the radar station have a great influence on the estimation error of the elevation angle. The method proposed in this paper is of simple principle and easy implementation, and it has a broad application prospect in the field of low-angle radar tracking and its anti-multipath interference.