The invention discloses a dodecahedral three-dimensional stress gage based on quantum dots. The dodecahedral three-dimensional stress gage comprises a box body (1). The box body is in a dodecahedral shape. Six adjacent surface of the box body are stress surfaces (2). Each stress surface (2) is provided with a groove (4) covered by a box body upper cover (3). A fixing device (6) for installing a four-needle quantum dot poly-nano-composite column body (5) is arranged in each groove. The top part of the four-needle quantum dot poly-nano-composite column body contacts the box body upper cover (3). An exciting light guiding end (9) and a light wave detector (10) are respectively installed on two adjacent side walls of the fixing device (6). A spectrometer (8) is connected with the light wave detector (10) through an optical fiber (7). An exciting light source (11) is connected with the exciting light guiding end (9) through an optical fiber (7). The dodecahedral three-dimensional stress gage has the advantages that six stress components can be measured at one time, the measurement reliability is improved, and the measurement accuracy is improved.