Disclosed are methods and devices for simultaneously detecting surface shapes and thickness distribution of inner and outer walls of a thin-walled rotating body. According to the invention, a chromatic confocal senor head is driven by a bottom rotary table, a main measuring head rotary table and a linear motion shaft mover to perform copy scanning along a surface of a thin-walled shell-type rotating body, so that the detection of the surface shapes and thickness distribution of the inner and outer walls of the thin-walled shell-type rotating body can be realized at the same time. By the method, mechanical interference caused by arranging a measuring head in the thin-walled shell-type rotating body can be avoided, and coordinate consistency of surface shape measurement data and thickness distribution data of the inner and outer walls in a three-dimensional space can be ensured, thus ensuring the overall measurement precision; and meanwhile.