Common Conversion Point (CCP) gather extraction is an important step in converted wave seismic data processing. It is also the main difference between converted wave processing and P-wave processing,and directly affects the results of velocity modeling and imaging. The conventional CCP gather selection and sorting method is still based on the whole trace selection and sorting,mainly the asymptotic approximation trace classification method,that is,the Asymptotic Conversion Point (ACP) gather extraction. This kind of method can satisfy the imaging requirements of deep strata to a certain extent,but it is difficult to guarantee shallow imaging effects. To solve this problem,this paper proposes a spatiotemporally variable conversion point gather extraction method. By calculating the spatial position of the CCP and combining the converted wave two-way traveltime,the mapping relationship between the input converted wave data and the output CCP gather is determined,and reflected seismic signals are mapped to accurate spatiotemporal locations. It can effectively handle asymmetric converted wave propagation paths,thereby effectively improving the extraction quality of CCP gathers. Numerical simulation and field data calculation results show that the CCP gather extraction method proposed in this paper has good practical application effects.