This paper introducesd the composition and working principle of the integrated magnetic switch based on fractional-turn ratio saturable pulse transformer. The integrated magnetic switch can realize the functions of solid-state magnetic switch, pulse modulation and voltage boost. Three typical applications of the integrated magnetic switch are also provided. First, it can be applied in high-voltage pulse trigger, which can realize the voltage greater than 100 kV, and jitter less than 5 ns at 30 Hz; Second, it is used for microsecond quasi-square pulse generation, producing larger than 50 kV and microsecond-range pulses continuously at 100 Hz; Third, as the main switch of the low-resistance pulse forming line, to output square pulses of 100 ns with dual-switch modulation technique to realize the lightweight of the pulse power device. The integrated magnetic switch based on fractional-turn ratio saturable pulse transformer is a compact pulse power device, which can take into account the high boost ratio of transformer and the low secondary saturation inductance of magnetic switch. It is of great significance for the realization of solid state and compactness of pulse power device.