The invention discloses a nutrient matrix for flower cultivation, comprising main ingredients and additives, the main ingredients include peat, perlite and vermiculite, the additives include matrix moisture conditioner, pH regulator and nutrient starter, peat, perlite and vermiculite The particle size is ≥4mm. The present invention also provides a method for preparing a nutrient matrix for flower cultivation, which includes the following steps: (1) uniformly mixing peat, perlite and vermiculite to prepare the main material of the matrix, and spraying a fungicide into the main material; (2) Firstly, add the substrate moisture conditioner to the main ingredients, then add the pH regulator to adjust the pH value of the substrate to 6-7, then add the nutrient starter, mix evenly to obtain the finished product of the cultivation substrate. The flower cultivation substrate prepared by the invention has balanced nutrition and stable physical properties, and obviously improves the water absorption of the peat substrate. Using the cultivation substrate of the invention to cultivate flowers improves the rooting rate of flowers, the leaves of flowers are large, the number of flower heads is large, and the height of plants is high. , the flowers grow vigorously.