Ancient DNA research has developed rapidly over the past few decades due to the improvement in PCR and next-generation sequencing (NGS) technologies, but challenges still exist. One major challenge in relation to ancient DNA research is to recover genuine endogenous ancient DNA sequences from the raw sequencing data. This is often difficult due to the degradation of ancient DNA and high levels of contamination, especially homologous contamination. In this study, we collected whole genome sequencing (WGS) data from 6 ancient samples to compare different mapping algorithms. To further explore more effective methods to separate endogenous DNA from the homologous contaminations, we attempted to recover reads based on the ancient DNA specific characteristics of deamination, depurination, and DNA fragmentation with different parameters. We propose a quick and improved pipeline for separating endogenous ancient DNA while simultaneously decreasing the homologous contaminations to a very low proportion. Overall, these recommendations for ancient DNA mapping and separation of endogenous DNA in this study could facilitate future studies of ancient DNA.