The integration of virtual scenes and reality is the current research hotspot and direction in many industries. In order to improve the immersive experience of traditional animation design, this paper proposes a virtual reality technology-based interactive animation design plan for the integration of human and natural environment. First, analyze the construction of virtual scenes of 3D animation; then, research on the integration technology of human and nature in virtual scenes, focusing on human body surface data collection, bone data extraction and virtual and real scene fusion; Finally, based on Unity3D The software has carried out the design practice of human and nature fusion interactive three-dimensional animation. Taking the interactive action of the human arm and the fireball as an example, it demonstrates the human fusion and interactive control of the fireball in the virtual scene. The research results of this paper have certain reference value for human-computer interactive 3D animation design.