Northeast China cold vortex (NCCV) often induces low temperature and cold damage in Northeast China during summer, resulting in "Dumb Disaster" to the "Northeast Granary". Using the fifth-generation reanalysis data of ECMWF, this paper analyzes the key circulation configuration, as well as formation and maintenance mechanism of NCCV with low temperature impact during early summer (May–June) over 1979–2021. The results show that two ridges over Lake Baikal and the Okhotsk Sea as well as NCCV form a typical inverted "Ω" circulation, which favors invasions of cold air and high potential vorticity from the high latitude region into Northeast China. At the same time, easterlies on the south flank of high over the Okhotsk Sea bring cold air into Northeast China. These two cold air intrusions together cause the abnormally cold in Northeast China. The "- + -" Rossby wave train from the eastern European Plain to Lake Baikal is the precursor of NCCV, which is incipiently amplified by the diabatic heating and friction. Subsequently, the Rossby wave plays a major role, which causes the high potential vorticity intruding southward and accumulating. The East Asian jet barotropically deforms such high potential vorticity to form a deep NCCV. As the downward dispersion of Rossby wave energy and the dissipation of diabatic heating and friction, NCCV weakens drastically. When the quasi-stationary ridge maintains over the north of Lake Baikal, it cuts off the connection between Northeast China and the cold air and high potential vorticity over the high latitude region. The Rossby wave hardly leads NCCV to develop and thus NCCV has no obvious low temperature impact over Northeast China.