In order to solve the problem of incomplete information in the reliability evaluation of ground test measurement systems for liquid rocket engines, the factors that affect the evaluation of ground test measurement systems for liquid rocket engines are analyzed in this paper. Firstly, the performance reliability index and functional reliability index are used as the measurement standards for the reliability of the measurement system, and the definition of the reliability of the ground test measurement system for liquid rocket engines is given. The uncertainty of the measurement system is incorporated as a performance reliability indicator into the measurement system reliability evaluation system, and the relationship between measurement uncertainty and classical reliability is established. Then, the number of failures of subsystem units is used as an evaluation indicator of functional reliability. A system reliability assessment strategy that integrates multi?source reliability information is developed. Afterwards, the principles and implementation methods of reliability data collection, reliability information conversion, reliability information synthesis, pyramid system reliability evaluation, and reliability evaluation based on expert linear weighting were elaborated. Finally, taking the ground test measurement system of a certain type of liquid rocket engine as an example, the reliability of the measurement system is evaluated. The results show that the pyramid comprehensive evaluation method that integrates multi?source reliability information can accurately analyze the reliability of the ground test measurement system of liquid rocket engines, and the expert linear weighted information fusion evaluation method can locate the key focus objects in the system and identify weak links. Not only does the research result provide new ideas and methods for technical personnel in the industry to study and evaluate the reliability of measurement systems, but it also has great significance for improving the quality of model products, measurement data quality, and system reliability.