A manufacturing method for memory includes: providing a substrate, and forming a first isolation layer and discrete bit lines on the substrate; removing part of the first isolation layer by a thickness to form discrete first trenches; forming word lines filling the first trenches, wherein the word lines each has a first side wall and a second side wall opposite to each other; forming discrete through holes each being between adjacent word lines; forming a first dielectric layer on surface of exposed first side wall, and forming a second dielectric layer on surface of exposed second side wall; and forming an active layer filling the through holes.