The invention provides a method for searching for a deeply-buried solid sylvite ore deposit and belongs to the mineral exploitation technology. The method includes the steps that firstly, the exploration drilling positions are arranged, wherein an anticline structure is found in a predicted sylvite ore deposit exploratory area, the highest point and the second high point are determined in the axial direction of the anticline structure, and the positions of drilling holes are arranged; secondly, drilling and sampling are conducted, wherein ore samples are acquired after drilling operation and drilling liquid does not contain potassium ions; thirdly, judgment is conducted, wherein ore samples acquired after drilling are observed, whether a lode containing potassium is found or not and whether a potassium-containing index occurs or not are judged; if an observation result in the third step shows the potassium-containing index, the exploratory area can be drilled continuously; if the observation result does not show the potassium-containing index, drilling operation is stopped, and the first step, the second step and the third step are conducted on another sylvite ore deposit exploratory area, wherein observation of the ore samples acquired after drilling means that drilling mud samples, rock debris samples and/or rock core and dyke samples are observed. By the adoption of the method, ore searching cost can be effectively reduced and the ore searching success rate of concealed potassium ores can be increased.