The invention relates to a fusarium fujikuroi mutant strain- fusarium fujikuroi GA-347 ( Fusarium fujikuroi GA-347 ) bred through an ARTP mutagenesis technique and an application of the fusarium fujikuroi mutant strain. The strain can be applied to industrial production in a large scale. The strain is preserved in China Center for Type Culture Collection, the address is Wuhan University, the postcode is 430072, the preservation No. is CCTCC NO:M 2019378, and the preservation date is 20 May 2019. In the growth process of the strain, conidium is not generated, the strain is inoculated to a liquid seed culture medium, and after cells grow to be mature, the cells are switched to a fermentation culture medium, so that the fermentation level is greatly increased, and the yield of gibberellin achieves 22 times of that of wild bacteria and leads in the national level. The gibberellin is in exocytosis, can be totally obtained from fermentation liquid, solid-liquid separation is facilitated, andthe extraction yield is increased. Besides, the utilization rate of equipment of raw materials is increased, the production cost is greatly reduced, and the strain has obvious economic benefits and social benefits.