Formula of color osmanthus plug cutting substrate on basis of earthworm cast and application method of formula

Disclosed are a formula of a color osmanthus plug cutting substrate on basis of earthworm cast and an application method of the formula. The color osmanthus plug cutting substrate is prepared by mixing the earthworm cast with a mineral material, the volume ratio of the earthworm cast to the mineral material is 9:1-3:7, livestock and poultry manure such as dairy manure is digested by earthworms, and then the earthworms are subjected to compost so as to obtain the earthworm cast, and the mineral material is one of perlite and vermiculite or a mixture of the perlite and the vermiculite. The rooting rate of color osmanthus can reach 60-80% at least mostly after the color osmanthus is subjected to cutting by the aid of the prepared substrate for 40 days, and root systems of the color osmanthus are fully distributed on cutting shoots.