The invention provides a system for simultaneous no-load demagnetization on multiple transformers. The system comprises a generator set, at least two parallel transformers with the same low-voltage rated voltage, an intermediate transformer connected between the generator set and the parallel transformers, and measurement instruments connected to leading-out terminals of the transformers, wherein a leading-in terminal of the intermediate transformer is connected to a three-phase terminal of the generator set, one phase in the leading-out terminal is connected to the leading-in terminals of the parallel transformers, another phase is short connected and the other phase is grounded; and one end of the leading-in terminals after the transformers are connected in parallel is connected to the leading-out terminal of the intermediate transformer and the other end is connected to a ground terminal, and the leading-out terminals of the transformers are connected to the measurement instruments. By the system for simultaneous no-load demagnetization on the multiple transformers provided by the invention, the feasibility of simultaneous demagnetization on multiple high-voltage and high-capacity transformers is achieved, the proportion of the occupied time of transformer no-load tests is reduced and the production cost is reduced.