“The replacement of isotope neutron sources with controllable sources for neutron porosity logging is an inevitable trend in the development of nuclear logging. To improve the feasibility and measurement accuracy of controllable D-D source neutron porosity logging, the influence of mud on D-D source neutron porosity logging was analyzed. Through Monte Carlo simulation, the response of shale in three neutron porosity logging processes was compared and analyzed; We optimized the source distance combination of D-D sources and analyzed how to weaken the influence of shale by changing the source distance. Research has shown that the response patterns of shale in D-D source and 241Am Be source are relatively similar. When the source spacing design of D-D source is closer than that of 241Am Be source, i.e. using a source spacing combination of 25-45 cm, the impact of shale on neutron porosity logging in D-D source is closest to that of 241Am Be source. Although the change in source distance combination cannot make the shale response of D-D source and 241Am Be source completely consistent or completely eliminate the influence of mud, this high degree of convergence provides ideas for shale correction in neutron porosity logging of D-D source, and also has certain application significance for compatible replacement of radioactive sources in logging instruments in the future.”