Abstract: By means of the four basic forms of the phenomenological method, the experimental research was carried out according to the principle of similarity criterion to simulate 2D pebble flow dynamics of high-temperature gas-cooled reactor. The result indicates that the test with circulating pebble-loading mode obviously presents better the situation in the real pebble bed reactor. The pebble flow dynamics spreads from bottom to top and from middle to sides. The movement of pebbles in central region is faster than that in annulus region and has no laminar characteristics performance. The mixed zone exists between central region and annulus region, and the distinct stagnant zone also exists at pebble bed bottom corner.