The invention provides a saturation reactor and a parameter setting method and device thereof, and a simulation device. A parallel branch formed by series connection of a branch resistor and a branchreactor is connected in parallel to the two ends of an existing main saturation reactor so as to transfer losses of the main saturation reactor, so that the losses are reduced and the temperature riseis reduced. Therefore, on the premise that the iron core material and overall structure of the main saturation reactor as well as the protection performance for the thyristor by the saturation reactor are not changed, the losses of the main saturation reactor are reduced and the temperature rise characteristic is optimized.