Appearance of the false lines is one of the major disturbing factors，which increases the complexity of the computation and reduces the stability of the extraction result，in the process of extracting artificial targets from high-resolution images. A robust two-step method is brought forward to filter the false lines extracted by the edge-based algorithms for extracting lines. Based on analysis of characteristics of false lines，in consideration that the lines extracted from artificial targets are regularly extraordinary，this method operates in two phase of the algorithms for extracting lines. One is that prior to grouping edges with co-lineation relationships，12 models are employed to filter a proportion of edges，from which the false lines may be fitted later.The other is that after the process of extracting lines， the strength of the similarity of the image characteristic close to the line is defined firstly，in terms of which the lines extracted are divided into the true ones or the false ones，and the false lines will be filtered. Lots of experiments show that this method can filter a majority of the false lines extracted from image，which are corresponding with image noise or irregular natural objects，while the true lines which are corresponding with artificial targets are almost preserved.