Healthcare security system is an important institutional arrangement that relieves the burden of medical treatment on the public, enhances people's well-being, and maintains social harmony and stability. It's the basic guarantee for this system that we establish a stable, healthy and sustainable financing and operation mechanism. It's particularly important to establish a stable, healthy and sustainable financing and operation mechanism while the demand for health increasing, the population aging situation becoming more severe, economic growth slowing, and medical costs increasing due to innovative development of medical technology. Firstly, this article elaborates the basic concept and characteristic of the healthcare security fund financing and operation mechanism. Secondly, this article objectively analyzes the current operation, the situation, problems and challenges of the basic medical insurance fund in China. Then, this article discusses how to optimize this mechanism, and puts forward corresponding suggestions. Finally, this article proposes the funding and operation mechanism to be established in the future.