The invention discloses a device and a method for judging the camber of a power semiconductor module base plate. The device comprises a measuring module, a processing module and a display module, wherein the measuring module carries out point taking operation on the surface of the power semiconductor module base plate, more than three measuring points are measured and taken on the surface of the power semiconductor module base plate, and in addition, space position data of the measuring points is transmitted to the processing module; the processing module carries out calculation and processing according to the space position data of the measuring points to obtain the space position data of a reference surface, further obtains and outputs difference value data of the space position data of the surface and the reference surface of the power semiconductor module base plate to the display module, outputs the planeness data, calculates the highest point position data of the base plate, and judges whether the data is qualified or not; the display module receives the difference value data transmitted by the processing module and generates diagrams, judges whether the diagrams are qualified or not, judges results by combining the data of the processing module, and outputs the final results. The device and the method have the advantages that the requirement of judgment on the outline of the power semiconductor module base plate can be met, and the concave surface, the convex surface and the planeness of the base plate can be fast and simply judged.