Abstract: The problem of safety rod accident dropped during C commissioning phase for China Advanced Research Reactor (CARR) was analyzed, and the reason was that the solenoid valve in safety rod drive mechanism (SRDM) driven loop was breakdown because of long-playing work. To solve this safe hidden trouble, SRDM was redesigned, and a new type of “hydro lifting-hydro and electromagnetic holding” SRDM was presented, using Ansoft Maxwell to make a finite element analysis on new SRDM, working out electromagnetic field distribution and electromagnetic force of new SRDM. The results show that the value of electromagnetic force produced by electromagnetic force holding unit reaches 2.12 times about the weight of safety rod drive line, and it has some margins.