Abstract: Through comprehensive analysis on the typical characters of steel hydrogen embrittlement in recent years, some new phenomenons, significantly affecting steel hydrogen embrittlement but always neglected, were found. For example, hydrogen embrittlement may sometimes occur to the material of low strength and low hydrogen content, Crow feet flaw on the crystal face of fracture surface decreases while the area of final rupture increases. Small size parts are more sensitive to hydrogen embrittlement, and hydrogen embrittlement may occur together with other failure modes. Some key problems to be solved were summarized, including no method which can be used to detect local hydrogen, no quantity relationship between strength and critical hydrogen content, and material strength above the upper limits. Some new knowledge was put forward to provide reference and experience for the design, manufacture, application and maintenance:material strength should be in the lower part of standard, and the regulations of dehydrogenation treatment should be made on the base of the practical material strength.