The invention relates to a macadimia nut seedling raising substrate preparation method based on macadimia nut waste, and belongs to the technical field of agricultural production. The macadimia nut seedling raising substrate preparation method comprises the following steps that 1, fermented macadimia nut peel is prepared; 2, carbonized macadimia nut shells are prepared; 3, macadimia nut branch and leaf powder is prepared; 4, the prepared materials are mixed with peat soil and yellow heart soil to prepare substrates; 5, the substrates are placed in seedling raising bags for standby application after being mixed evenly. According to the macadimia nut seedling raising substrate preparation method based on the macadimia nut waste, waste such as pruned branches and leaves in a macadimia nut orchard and the peel and the shells generated in fruit primary processing can be effectively and reasonably utilized, the macadimia nut waste is prevented from polluting the environment, and the utilization value of the macadimia nut waste is improved; the substrates prepared through the method are rich in nutrition, loose and breathable and can retain water and fertilization, and root system development and plant growth of macadimia nut seedlings can be promoted; meanwhile, the preparation method is simple, low in cost and convenient to operate and transport.