The present invention relates to a semiconductor memory cell structure, a semiconductor memory as well as preparation method and application thereof. The semiconductor memory cell structure includes: a substrate; and a first transistor layer, an isolation layer and a second transistor layer. The first transistor layer includes a first stack structure formed by stacking a first source, a first channel, and a first drain from bottom to top; and a first gate located on a sidewall of the first stack structure. The second transistor layer includes: a second stack structure formed by stacking a second drain, a second channel, and a second source from bottom to top; and a second gate located on a sidewall of the second stack structure, at least a part of a sidewall of the second drain is in direct contact with the first gate. The present invention provides a 2T0C type DRAM cell with an improved structure, has the advantages of vertical stack integration, high integration level, low leakage current, short refresh time and the like, and is significantly superior to the existing 2T0C type DRAM.