Aiming at the problems such as the closed encoder protocol of the displacement actuator of the spliced mirror telescope and the high power consumption and large volume of the existing decoding schemes, a high-precision position feedback system based on SoC-FPGA technology is proposed to realize the open decoding of the EnDat2.2 protocol, in order to meet the requirements of miniaturization, low power consumption and high integration for domestic substitution. The PS-PL collaborative processing architecture is constructed using the Zynq-7000 platform. The PS end uses the dual-core Cortex-A9 core to complete system control and communication scheduling. The PL end implements Manchester codec and CRC-5 verification through hardware logic. Design a driver interface circuit centered on ADM1485 and ADuM1301 to enhance the anti-interference capability. And the IDELAYE2 module is utilized for dynamic timing compensation to solve the problem of data phase offset caused by physical link differences. Experiments show that the position feedback accuracy of the system reaches 368 nm. Large-scale error injection tests demonstrate that the CRC-5 verification achieves a detection success rate of 99.99% at a 0.2% error rate, while the PCB volume is reduced by approximately 31.6% and the power consumption is lowered by more than 11 times. This solution successfully realizes high-reliability decoding of the EnDat2.2 protocol, providing crucial technical support for the miniaturization, low power consumption and high integration of displacement control systems in China′s astronomical telescopes and high-precision numerical control equipment. It holds significant engineering application value and potential for independent promotion. Future work may further optimize algorithms to enhance stability under extreme conditions.