Abstract: Abundant data generated by drilling engineering is not analyzed and processed effectively and the related problems are not researched thoroughly. In addition, well sites and bases are lack of timely technical interactivity and remote support. In order to solve these problems, an assistant decision-making system for well drilling was established. Then, a real-time dynamic drilling and completion database was studied and newly built, and the drilling engineering calculation models (e.g. coupled hydrodynamic model, friction and torque model and ROP optimization model) were integrated with drilling simulator as the core, and thus real-time dynamic simulation, three-dimensional visualization and remote drilling monitoring in the process of drilling is realized. Finally, based on its application in 9 wells of BZ19-6 exploration project, combined with friction coefficient inversion method, hydraulic simulation fitting method and stage correction method, the simulation accuracy of friction and torque and hydraulic parameter was 90% and the monitoring accuracy of formation pore pressure was 97%. What's more, remote technical support based on expert consultation has been carried out accumulatively over 20 times. And eventually, a set of structure and method of remote assistant decision-making system for well drilling based on transient data simulation analysis was established.