The invention discloses an automatic flow adjusting device which comprises a mounting shell, a water inlet
pipe communicated with a water inlet of a
server liquid cooling system, a water outlet
pipe communicated with a water outlet of the
server liquid cooling system, a mechanical control valve arranged on the water inlet
pipe and used for controlling the water
inlet flow of the water inlet pipe, and a driving mechanism arranged on the water outlet pipe. The transmission mechanism is connected between the output end of the driving mechanism and the control end of the mechanical control valve, the driving mechanism is filled with a working medium which is used for expanding with heat and contracting with cold under the temperature action of the water outlet pipe so as to drive the output end of the driving mechanism to reciprocate, and when the working medium expands with heat, the transmission mechanism drives the mechanical control valve to increase the opening degree; and when the working medium shrinks cold, the transmission mechanism drives the opening degree of the mechanical control valve to be reduced. The cooling liquid flow can be dynamically adjusted according to the actual heating condition and the heat dissipation requirement of the
server, and the proper heat dissipation performance is guaranteed. The invention further discloses the liquid cooling server, and the beneficial effects of the liquid cooling server are as mentioned above.