The connotation of the "four-dimensional pivot-earth" qi transformation mode is a dialectical system of the ascending and descending of yin-yang qi movement， which presented as "the middle Jiao showing earth qi mediating， the left wheel showing water and wood ascending， and the right wheel showing fire and metal converting and descending". Based on this dialectical thinking， it is believed that the core pathogenesis of myasthenia gravis is deficiency of center qi and transportation failure to pivot-earth； the middle-stage characteristics of the disease progression are the loss of mediation of the central qi， resulting in water coldness and wood constraint， and clear yang failing to ascend； the final outcome of this disease is the loss of astringeing of lung metal and qi sinking. The treatment should be based on the rule of qi movement， so for the start-stage， Buzhong Yiqi Decoction （补中益气汤） should be used as the basis to nourish the earth and consolidate the root， and restrengthen the middle qi； for the middle-stage， herbs like Yingyanghuo （Epimedium brevicornu Maxim.）， Bajitian （Morinda officinalis How） could be combined to warm the water and soothe the wood， raise yang and boost qi； for the final stage， plus Sini Decoction （四逆汤） to astringe metal to stop collapse， and powerfully supplement original qi. All these medicinals can promote pivot-earth re-transportation， four-dimensional transformation， and regular circulation of qi movement， so as to provide thoughts for improving the clinical effectiveness of myasthenia gravis.