The invention provides an artillery rotating radius and pitch radius detecting device and method based on a laser radar, and belongs to the field of laser measurement. On the basis of a laser radar technology, the artillery rotating radius and the pitch radius are indirectly measured by combining the artillery rotating radius and pitch radius detecting device based on the laser radar and using the similar triangle principle. The device comprises a rotating hand wheel, a lead screw, a spring ring, a sleeve, a positioning block, a conical body block, a laser radar and a plug gauge, wherein the rotating hand wheel is connected with the lead screw, the lead screw is arranged inside the sleeve and is coaxial with the sleeve, the positioning block is positioned at the outer side of the sleeve, the positioning block is connected with the sleeve through the spring ring, and the laser radar and the plug gauge are independent devices and are matched with the positioning block for completing the detection. The device and the method provided by the invention have the advantages that the rotating radius and the pitch radius of an artillery can be precisely measured, the measuring precision can reach the micrometer level, the measuring precision is greatly improved, in addition, the structure of the detection device is simple, the measuring process is simple, the implementation is easy, and the detection capability and the shaping test level of the shooting range artillery can be improved.