(This is a basic theoretical research work of interior design based on rich practical experience. With simple and easy to understand discussion methods and vivid examples, this paper systematically expounds how to correctly use creative thinking and design in interior design. The content is introduced from four aspects: the theoretical basis of interior design; Characteristics of interior design system; Design thinking and expression; Design language and design method. It describes in detail the essence of design, artistic feeling, scientific logic, creative basis, concept of space-time system, spatial design elements, behavioral psychological factors, concept and conception, scheme and expression, structure and details, design language, graphic method, function and plane, image and space, etc.This book can be used as a teaching reference book for teachers and students majoring in interior design, architectural decoration and environmental art in Colleges and universities. Good work and study instructions.)