The invention discloses a high-precision electronic balance measuring system based on a single sensor. The high-precision electronic balance measuring system comprises the single sensor, an electromagnetic force balance mechanism, a photoelectric detection sensor, a PID proportion control circuit, a temperature and humidity sensor, a magnetic cylinder coil signal conditioning circuit, a CPU microprocessor circuit and a liquid crystal display circuit. The single sensor is arranged above the electromagnetic force balance mechanism and fixedly connected with a magnetic cylinder in the electromagnetic force balance mechanism. The high-precision electronic balance measuring system has the advantages that a coil is installed below the tail of a long rod of the single sensor and is arranged in the magnetic cylinder to be coupled with the magnetic cylinder, the photoelectric detection mechanism detects the displacement of a displacement mechanism, a high-precision measuring control circuit processes voltage signals produced by the photoelectric detection mechanism according to the electromagnetic force feedback balance null method principle, the coil generates the current to carry out feedback adjustment, the displacement mechanism recovers to the initial position, and the weight of a weight to be weighted is measured when the balance state is kept. The high-precision electronic balance measuring system has the advantages of being high in precision and speed, good in stability and reliability and the like.