Cremastra appendiculata (D. Don) Makino is a rare perennial medicinal plant with significant medicinal and ornamental value. Its seeds exhibit a low germination rate in nature due to the species’ dependency on fungi to facilitate germination. Pre-laboratory studies have shown that symbiotic fungus Coprinus radians (Desm.) Fr. from the rhizomes of wild C. appendiculata that significantly promote its seeds germination and seedlings development. The growth of symbiotic fungi directly affects seed germination and seedling development. In order to obtain high-quality strains of the symbiotic fungus C. radian, the growth characteristics and culture conditions were investigated, which mainly include the temperature, light intensity, pH and nutrient supply suitable for growth. This study conducted single-factor experiments to screen and optimize the formulations and culture conditions for the parental strain, primary strain, and cultivation strain of C. radian, building on this foundation, the symbiotic seedling cultivation of C. radian with C. appendiculata was optimized to explore the best conditions. The results revealed that the suitable conditions for the cultivation of the parental strain of C. radian. Subsequently, The formulation suitable for the cultivation of the primary and cultivation strains was a mixture of willow wood, cottonseed hulls and sweet potato flour in a ratio of 8:1:1 with a water content of 30%. The symbiotic seedling cultivation methods were feasible. Results of these studies have screened suitable culture conditions for the strains of C. radian and conducted preliminary experiments for the establishment of symbiotic seedling propagation technology for C. appendiculata.