In the traditional Raman-distributed optical-fiber temperature measurement system, the spatial resolution, temperature accuracy, sensing distance, and signal-to-noise ratio of the system are restricted by the sampling rate, signal quantization bits, onboard memory, and data processing ability of the data acquisition and processing module, preventing the system from performing at its full capacity. This paper presented the design of a data acquisition and processing module for long-distance Raman-distributed optical-fiber temperature measurement system based on field programmable gate array (FPGA). The module used the technique of AXI4 bus time-sharing burst read and write DDR3 memory to achieve the real-time cumulative and average processing of ultra-long data. Furthermore, the module realized data transmission between the FPGA and host computer utilizing the user datagram protocol (UDP) communication protocol and used the upper computer to demodulate and display the received data. Experimental results show that the proposed data acquisition and processing module can be applied in the optical-fiber signal acquisition range of 89.6 km, with the signal-to-noise ratio reaching 43.65 dB. Moreover, the temperature measurement accuracy is stable at ±0.21 ℃ under the 100000 times cumulative average processing of the temperature measurement signal. Thus, the data acquisition and processing module can further promote the application and development of Raman-distributed optical-fiber temperature measurement system.