The invention provides an AC-side power dissipation device. The device comprises two groups of modules which have the same structure and are connected in parallel. Each group of modules comprises a three-phase reactor and a thyristor rectifier bridge. The first end of the reactor is connected with an AC three-phase bus, and the second end of the reactor is connected with the thyristor rectifier bridge. The upper and lower bridge arms of each phase of the thyristor rectifier bridge respectively comprise two or two groups of thyristors. The upper and lower bridge arms are provided with bypass thyristors. The bridge arm bypass thyristors of the two groups of modules are correspondingly connected in pairs in a staggered manner. The DC ends of the thyristor rectifier bridges of the two modulesare connected in parallel and then connected with an energy consumption resistor R. In a non-fault state, the device is converted from a CHOPPER circuit to a TCR circuit, and the reactive power is transmitted to a system. Therefore, the utilization rate of the power dissipation device is greatly improved. The power dissipation device, which originally only works in the the condition of an emergency fault in the prior art, becomes a common device. As a result, the overall cost of a project is saved.