This book, compiled based on the author’s years of research and teaching experience, introduces criminal investigation and infrared image overview in a simple and profound manner. It also elaborates on the theory of artificial immune intelligent algorithm based on the collaborative mechanism between innate immunity, adaptive immunity, endocrine system, and nervous system, and illustrates the application of artificial immune algorithm in various criminal investigation infrared image processing fields with practical infrared image examples. The book covers a wide range of frontier biological immune algorithms and their applications in target extraction and recognition of criminal investigation infrared images. With a moderate level of difficulty, this book is not only suitable as a textbook for courses such as “Infrared Image Processing” or “Criminal Investigation” for public security criminal investigation, image processing, artificial intelligence, computer, and related experts, but also as a reference book for technicians to learn criminal investigation techniques.