Abstract: Modern precise managed pressure drilling technology proposes higher requirements on control accuracy of wellhead back pressure,but because of intense nonlinear relationship between pressure regulation characteristic and opening presented on throttle valve,it is difficult to achieve accurate regulation through single throttle valve within the scope of full opening for the current choke manifold.In the purpose of meeting the requirements of control accuracy of back pressure with traditional throttle valves,based on the research of flowing characteristic of parallel pipelines,this paper put forwards a thinking of realizing fine back pressure control by means of parallel choke manifold,and the pressure regulation characteristic of parallel choke manifold was analyzed by simulating the working process of parallel choke manifold with four branches that accurately control wellhead back pressure.Compared with the traditional choke manifold,parallel choke manifold has good linearity of characteristic curve on pressure regulation,larger regulation range,higher regulation accuracy,lower accuracy demand and longer service life of throttle valves and other obvious advantages,which have significant engineering meaning and economic benefit.This provides some technical references for further study on fine managed pressure drilling and ground control system.