This self-adapted telemetry frame synchronizer is designed for certain UAV, which telemetry-data frame-format is altering with different working modes. This frame synchronizer is controlled by software, so its parameters can be adjusted on real time to adapt various frame-formats. After that, EPROM is applied to achieve correlation-detect, and FPGA to form peripheral circuit. Through elaborate design, it can work on 4M bps. Based on performance analysis, the parameters of the synchronizer are optimized to meet the needs. Recent test-fly approve that it can work steadily and measure all design targets.