The invention relates to a method for measuring whole-process annular pressure. A parameter measurement function under a pump starting state and a pump stopping state is realized, important data including the largest fluctuating pressure, static and dynamic stability pressure, changes of pressure differences inside and outside a column, and the like in the well drilling operation process is intelligently detected and timely uploaded to a ground system for comprehensive analysis, downhole complex situations and accidents are avoided, operations of well drilling and well completion are safely and quickly guided, and operation risks and well drilling cost are reduced.