Abstract: Hydraulic control rod drive technology (HCRDT) is a newly invented patent with Institute of Nuclear and New Energy Technology of Tsinghua University which owns HCRDT’s independent intellectual property rights. The integrated valve which is made up of three direct action solenoid valves is the key part of this technology, so the performance of the solenoid valve directly affects the function of the integrated valve and the HCRDT. The electromagnetic field of 8 types of the direct action solenoid valve was analyzed using the ANSYS software with various currents, the results of which were validated by experiments. It shows that the magnetic force increases with the increasing current and the magnetic force of the solenoid valve with straight-angel armatures increases much faster. Furthermore, different shaped interfaces of the annular airproofing structure between armatures lead to different results. At last, the subsection of magnetic material accelerates the magnetic force sharply.