Wet non-woven fabric, preparation method therefor and water treatment membrane containing wet non-woven fabric

A wet non-woven fabric, wherein the wet non-woven fabric has an average pore size not greater than 10 µm, a maximum pore size not greater than 40 µm, and a maximum pore size/average pore size ratio not less than 1 and no greater than 12;

• the wet non-woven fabric, as a whole, is of a single-layer structure formed of at least two layers combined together, wherein the at least two layers comprise a first layer and a second layer;
• the first layer is composed of backbone fibers with a fibre number not greater than 9.20 µm and binder fibers with a fibre number not greater than 11.27 µm, and the second layer is composed of backbone fibers with a fibre number not greater than 13.01 µm and binder fibers with a fibre number not greater than 14.55 µm;
• and
• the fibre number of the backbone fibers of the first layer is not greater than that of the backbone fibers of the second layer, and the fibre number of the binder fibers of the first layer is not greater than that of the binder fibers of the second layer.