Against the backdrop of accelerating iteration in global artificial intelligence (AI) technology and the restructuring of the innovation ecosystem, corporate AI innovation has become the core engine driving industrial upgrading and enhancing national competitiveness. As the external ecological carrier for corporate innovation activities, the synergistic configuration of the multi-dimensional elements of the business environment increasingly highlights its enabling effects on AI innovation. This paper focuses on the influence mechanism of the business environment on corporate AI innovation, integrating the fsQCA method with a complex mediation model. Using data from 250 Chinese cities and listed companies in the ICT industry from 2017 to 2022 as the sample, it explores the complex pathways through which different elements of the business environment influence AI innovation via corporate R&D enthusiasm. The study identified four configuration pathways driving high R&D enthusiasm： market-talent dual-core driven, market-financial synergistic empowerment, manpower-government synergistic governance, and multi-complementary synergies in the rule of law process, and proposed that different business environment configurations influence high corporate R&D enthusiasm through resource supply effects, institutional friction-reduction effects, and risk mitigation effects. Furthermore, this paper argues that R&D enthusiasm ultimately drives AI innovation by enhancing the level of basic research under the impetus of AI market demand. This paper not only reveals the configuration effects and transmission mechanisms of the business environment on AI innovation through a complex mediation model but also provides differentiated path references for local governments to optimize the business environment and precisely stimulate corporate AI innovation vitality.