Rocket propellant is an important part of the rocket. Solid or liquid propellant will burn in the engine combustion chamber, and then a large amount of high-pressure gas will be generated. High-pressure gas will be ejected from the engine nozzle at a high speed, generating a reaction force on the rocket, so that the rocket will advance in the opposite direction of the gas injection. This paper mainly analyzes the advantages and disadvantages of current propellants and conceives a theoretically feasible propellant selection method. The main method of research is to calculate the theory of each propellant and make diagrams. Some of the research data were based on existing research reports. Each fuel has its own characteristics, they have one aspect of excellent ability, such as heat conduction, high thrust, high reliability. This paper summarizes the characteristics of current propellants and provides a more convenient query for future researches.