With the development of smart highways, the processing and storage of high-frequency and large-scale highway structural health monitoring (SHM) data face significant challenges. Traditional data compression methods struggle to maintain a high compression ratio while retaining all critical information. Therefore, we design a lossless compression method tailored to the characteristics of SHM data, and based on the method, we develop SHMComp, a system for highway monitoring data compression. The system combines lossless and lossy compression techniques, allowing users to upload structural health monitoring (SHM) data and download compressed results, thereby reducing storage requirements. We evaluate the performance of our system through metrics, such as compression ratio and distortion.