A grinding machine for grinding non-horizontal grinding surfaces, comprising: a grinding power source and a grinding pad driven by the grinding power source to perform a grinding stroke on a non-horizontal grinding surface, the grinding pad being made of an elastic material and being configured to take a deformed state for adapting to the non-horizontal grinding surface; and a deformation device disposed between the grinding power source and the grinding pad , the deformation device comprising at least one receiving unit for holding the grinding power source and two offset units disposed between the grinding pad and the receiving unit , wherein the receiving unit defines a reference horizontal line and the two offset units are respectively disposed near two opposite ends of the receiving unit , said deformation device further comprising at least one first deformation member connected between each of the offset units and the receiving unit ; wherein, when the grinding pad performs the grinding stroke on the non-horizontal grinding surface to generate the deformed state, the at least one first deformation member is able to be deformed independently to define a first deformation angle (R1) formed between anyone of the offset units and the reference horizontal line of the receiving unit , characterized in that said deformation device further comprises at least two second deformation members disposed oppositely and connected between each of the offset units and the grinding pad , wherein, when the grinding pad performs the grinding stroke, the at least two second deformation members are able to be deformed to define a second deformation angle (R2) formed between the grinding pad and the reference horizontal line of the receiving unit . a grinding power source and a grinding pad driven by the grinding power source to perform a grinding stroke on a non-horizontal grinding surface, the grinding pad being made of an elastic material and being configured to take a deformed state for adapting to the non-horizontal grinding surface; and a deformation device disposed between the grinding power source and the grinding pad , the deformation device comprising at least one receiving unit for holding the grinding power source and two offset units disposed between the grinding pad and the receiving unit , wherein the receiving unit defines a reference horizontal line and the two offset units are respectively disposed near two opposite ends of the receiving unit , said deformation device further comprising at least one first deformation member connected between each of the offset units and the receiving unit ; wherein, when the grinding pad performs the grinding stroke on the non-horizontal grinding surface to generate the deformed state, the at least one first deformation member is able to be deformed independently to define a first deformation angle (R1) formed between anyone of the offset units and the reference horizontal line of the receiving unit , characterized in that said deformation device further comprises at least two second deformation members disposed oppositely and connected between each of the offset units and the grinding pad , wherein, when the grinding pad performs the grinding stroke, the at least two second deformation members are able to be deformed to define a second deformation angle (R2) formed between the grinding pad and the reference horizontal line of the receiving unit . <EOS>