Liquid cooling system, charging host and charging system

The embodiment of the utility model provides a liquid cooling system, a charging host and a charging system. The liquid cooling system comprises a flow resistance adjusting structural member, a cold source assembly and at least one liquid cooling plate. And a liquid cooling cavity for accommodating cooling liquid is formed in each liquid cooling plate. Each liquid cooling plate is provided with a first opening and a second opening, and the first opening and the second opening are communicated with the liquid cooling cavity. The input end and the output end of the cold source assembly communicate with the first opening and the second opening correspondingly. And the flow resistance adjusting structural member is arranged at the first opening or the second opening, so that the flow of the cooling liquid passing through the first opening or the second opening can be changed, and the flow of the cooling liquid in the liquid cooling plate is equal to the cooling liquid demand required by the power assembly corresp