As an important parameter in the development and testing of rocket engines, temperature plays a guiding role in the design and improvement of rocket engines. Due to the complex working environment, strong electromagnetic interference, and high dynamic impact of rocket engines, higher requirements are placed on the reliability of temperature acquisition equipment. After studying the transient temperature testing of rocket engines, a multi-channel transient temperature testing system was designed. The system consists of thermocouples, temperature acquisition devices, and upper computer. The system converts temperature signals into analog voltage signals through thermocouples. The temperature acquisition device records the analog voltage signals from the thermocouples and stores them in the built-in storage chip. The temperature signals are transmitted, analyzed, and processed by connecting to the upper computer. Through a large number of experiments to verify the system's functions and performance indicators, it has been proven that the transient temperature testing system has high accuracy and reliability, and can achieve temperature testing of rocket engines.