High-precision safe-type delay element

The invention relates to a high-precision safe-type delay element and belongs to parts for a delay detonator. The high-precision safe-type delay element is characterized in that (1) a delay explosive of which the chemical agent components comprise red lead, silicon powder, a burning rate modifier and a binder, wherein by precisely controlling the particle size and purity of the components, the chemical agent is subjected to aging treatment so that the storage performance and delay precision became stable; (2) structure of the delay element comprises a delay explosive as an inner layer, a hard metal restraint tube as a secondary layer and a metal wrap layer which has small thermal conductivity and low heat energy and is ductile as an outer layer; (3) preparation of the delay element is achieved by the following steps that the hard metal tube with desired specifications is selected, a metal hose sleeves the hard metal tube and is drawn and precisely cut into the restraint element with a desired length; and (4) explosive charging is performed, specifically the explosive is quantitatively press-charged into a delay explosive core with uniform density for many times under a constant pressure in a special device. Due to the precise control of the explosive charging and the effect of the outer wrapping layer, the delay element can be used for the assembly of industrial delay electric detonators or nonel tube detonators, and is especially suitable for the assembly of coal mine type millisecond delay electric detonators and thus the precision delay is completed.