Electronic analytical balances generally use the method of pulse width modulation current to precisely adjust the electromagnetic force, and it is difficult to achieve a million-degree accuracy in engineering. After analyzing the influence factors of traditional methods on measurement accuracy, an improved pulse width modulation current circuit with double closed-loop control is designed, which decouples the previous PID control circuit and current measurement hybrid circuit, reduces the difficulty of PID parameter tuning and solving the difficulty of the system transmission equation of the mechanical sensor and balance detection channel, and improves the response speed and measurement accuracy. Experimental data show that, without nonlinear correction and only with moving average filtering, the original measurement data of an electronic analytical balance with a 31 g-range can achieve an accuracy of one million divisions with standard deviation of 2×10 -5 g, which is ten times better than the original 220 g-range electronic analytical balance with the same circuit and sensor