Reliability assessment is an important technical means to ensure the safe and normal operation of mechanical equipment. Circulating pumps used in aerospace equipment need to experience extreme environments during the rocket launch phase and the spacecraft in orbit phase. In order to study the reliability of the circulating pump in extreme environments such as rocket launch and spacecraft in orbit, a complete set of Reliability test system, several simulation experiments have been carried out, and relevant data have been collected. This paper uses time-domain characteristic parameter analysis and wavelet denoising-Hilbert envelope analysis to analyze and process the vibration signals collected during the simulation experiment. According to the analysis results, the reliability of the circulating pump is evaluated. The results show that the reliability of the circulating pump meets the requirements for use of aerospace equipment in extreme environments.