In order to meet the needs of wideband fiber-optic time delay line with high-precision and large dynamic range, a time-stabilized 9bit wideband fiber-optic delay line is designed and demonstrated with magnetic optical switches and phase stable fiber. The experimental results show that, the sample can realize a transmission frequency of 1~18GHz in a wide temperature range of 60℃, the delay range is 0~2555ns with a delay step of 5ns, and the delay precision is less than ±5.8ps. Meanwhile, for a certain delay point, the dynamic range is 600ps and the precision is less than 1ps.