The present invention relates to a water level controller for automatically replenishing a solution tank, comprising: a control box placed in the solution tank； a valve disposed at the top of the control box and sleeved with an external inlet pipe An upper cover covering the top end of the valve, and having a water inlet hole therein for communicating with the water inlet pipe, wherein the valve performs water supply and water stop by controlling the opening and closing of the water inlet hole by rising and falling； And at least one decompression opening is disposed at a bottom end of the control box for draining water, wherein when the water level of the solution tank is lowered to the at least one decompression opening, the valve is automatically raised by the position of the cam protrusion To start hydrating.本創作係有關一種用於一溶液箱自動補水之水位控制器，包括：一控制盒，置放於該溶液箱內；一閥門，設置於該控制盒之頂端並與一外接之進水管套接；一上蓋，覆蓋於該閥門之頂端，其內具有一進水孔，以與該進水管相通，其中該閥門藉由上升與下降以控制該進水孔之啟閉而進行補水及止水；以及至少一個減壓開口，設置於該控制盒之底端，用以洩水，其中於該溶液箱之水位降低至該至少一個減壓開口時，利用該凸輪凸起位置將該閥門瞬間頂高，以啟動補水。
